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The Myxomycetes of the Miami Valley, Ohio
by A. P. Morgan
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From the Journal of the Cincinnati Society of Natural History, Oct. 1892, Jan. 1893.

THE MYXOMYCETES OF THE MIAMI VALLEY, OHIO.

BY A. P. MORGAN.

First Paper.

(Read January 3, 1893.)

Table of Contents

MYXOMYCETES, Wallr.

Order Genera Page LICEACEAE. 4 Licea 4 Tubulina 6 Lycogala 7 RETICULARIACEAE. 10 Reticularia 10 Clathroptychium 12 Cibraria 13 Dictydium 16 PERICHAENACEAE. 19 Perichaena 19 Ophiotheca 21 ARCYRIACEAE. 23 Lachnobolus 23 Arcyria 24 Heterotrichia 27 TRICHIACEAE. 28 Hemiarcyria 29 Calonema 33 Trichia 34 Oligonema 40 STEMONITACEAE. 43 Clastoderma 44 Lamproderma 45 Comatricha 48 Stemonitis 52 Enerthenema 56 Diachaea 56 DIDYMIACEAE. 58 Didymium 59 Spumaria 64 Diderma 66 Lepidoderma 72 PHYSARACEAE. 73 Angioridium 75 Cienkowskia 75 Leocarpus 76 Physarella 78 Cytidium 80 Craterium 84 Physarum 88 Fuligo 102 Badhamia 105 Scyphium 109

List or Illustrations

Vol. XV. Plate III. Figs. 1-12. Vol. XVI. Plate I. Figs. 13-24. Vol. XVI. Plate XI. Figs. 25-36. Vol. XVI. Plate XII. Figs. 37-48. Vol. XIX. Plate XIII. Figs. 49-55. Vol. XIX. Plate XIV. Figs. 56-63. Vol. XIX. Plate XV. Figs. 64-73.

PRESTON, HAMILTON COUNTY, OHIO, December 28, 1892.

MR. DAVIS L. JAMES

Dear Sir—Along with this I send you the first installment of the papers, entitled "The Myxomycetes of the Miami Valley, Ohio."

The work in these papers is based upon my ample collection of Myxomycetes growing in this region, comprising more than one hundred species; these have been diligently compared with specimens obtained from correspondents elsewhere in this country and in Europe.

At the same time, I have also included many extra limital species. This has been done chiefly to more clearly elucidate the subject in places where the local material is not sufficient.

The only apology I can make for the arrangement which I present, is that I have been obliged to choose from several different systems. I have aimed not to hamper myself, by attaching paramount importance to some particular character throughout.

I purpose to furnish a synopsis of the whole at the end of the work.

Very truly yours, A. P. MORGAN.

* * * * *



MYXOMYCETES, Wallr.

Fructification essentially a minute membranaceous vesicle, the SPORANGIUM inclosing the SPORES, the product of a motile protoplasmic body called the PLASMODIUM.

Microscopic organisms with the habit of the Fungi. The ripe spore of the Myxomycetes is globose or ellipsoidal in shape, with the epispore colorless or colored, and smooth or marked by characteristic surface—sculpture according to the species; the spore in germination gives rise to an elongated protoplasmic body, which exhibits amoeboid movements, and is known by the name of swarm-cell. The swarm-cells multiply by bipartition, which may be repeated through several generations; they then unite together to form the large motile protoplasmic bodies named plasmodia. The newly-formed plasmodium is distinguished by its greater size from the swarm-cells, while it exhibits essentially the same movements and changes of shape. The plasmodia gradually increase in size, and as they grow assume commonly the form of branched strands; these spread over the surface of the substratum, which is usually the decaying parts of plants, in the form of veins and net-works of veins, giving rise to a copiously-branched reticulated or frill-like expansion, which covers surfaces varying in extent from a few to several centimeters. They are chiefly composed of a soft protoplasm of the consistence of cream, which may be readily spread out into a shapeless smear, and is usually colorless, but sometimes exhibits brilliant colors of yellow, orange, rose, purple, etc. The development of the plasmodium ceases with the formation of the spores within their sporangia.

The formation of the sporangia out of the plasmodium appears under three general forms, which, however, pass into each other and are, therefore, not strictly limited.

First: An entire plasmodium spread out on its substratum becomes transformed into a sporangium, or it divides into a variable number of unequal and irregular pieces, each of which undergoes transformation. Such a sporangium lying flat on the substratum, more or less elongated and flexuous, often branched and reticulate, is termed a plasmodiocarp.

Second: Erect sporangia on a narrow or stalk-like base, begin as node-like swellings on the branches of the plasmodium, and gradually rise to their ultimate form as the surrounding protoplasm flows into them and assumes an upward direction. These sporangia are nearly always perfectly regular in shape; they may be globose, obovoid, somewhat depressed, or more or less elongated, and are either stipitate or sessile.

Third: A number of plasmodia collect together from every side and become fused into a single body, often of considerable dimensions; from these combinations originate the large spore-receptacles which are called aethalia. The component sporangia may be regular in shape, standing close together, in a single stratum, with entire connate walls; more often, being elongated and flexuous, they branch and anastomose freely, their walls becoming perforated and more or less defective; in other cases, the aethalium is a compound plasmodiocarp, the narrow sinuous sporangia branched and anastomosing in all directions, forming an intricate network, closely packed together and inseparable. The surface of the aethalium is often covered by a continuous layer of some excreted substance, which is called the common cortex.

The wall of the sporangium, typically, is a thin, firm membrane, colorless and pellucid, or colored in various shades of violet, brown, yellow, etc.; it is sometimes extremely delicate, as in Lamproderma, or is scarcely evident, as in Stemonitis; in other instances it is thickened by deposits on the inner surface, as in Tubulina, or by incrustations on the outer surface, as in Chondrioderma. The stipes are tubes usually with a thick wall, which is often wrinkled and folded lengthwise, and is confluent above with the wall of the sporangium; in some cases the stipe also enters the sporangium, and is more or less prolonged within it as a columella. The stipe commonly expands at the base into a membrane, which fastens it to the substratum, and is called the hypothallus; when all the stipes of the same group of sporangia stand upon a single continuous membrane, it is called a common hypothallus.

In the simplest forms, the cavity of the sporangium is filled exclusively with the numerous spores; but in most all of the genera, tubules or threads of different forms occur among the spores and constitute the capillitium. The capillitium first makes its appearance in Reticularia, in which upon the inner surface of the walls of the sporangia there are abundant fibrous thickenings; next in Cribraria it is spread over the inner surface of the wall, and is early separated from it; here, also, it first assumes a more definite form and arrangement; in Physarum it is in connection with the wall of the sporangium only by its extremities while it traverses the interior with a complicated network; in Stemonitis and its allies the capillitium originates wholly from the columella; in most species of Arcyria it issues from the interior of the stipe. The capillitium in Trichia consists of numerous slender threads which are free, that is, are not attached in any way; they are usually simple and pointed at each extremity; the surface of these threads exhibits beautiful spiral markings.



ORDER I. LICEACEAE.

Sporangia always sessile, simple and regular or plasmodiocarp, sometimes united into an aethalium. The wall a thin, firm, persistent membrane, often granulose-thickened, usually rupturing irregularly. Spores globose, usually some shade of umber or olivaceous, rarely violaceous.

The species of this order are the simplest of the Myxomycetes; the sporangium, with a firm, persistent wall contains only the spores. There is no trace of a capillitium, unless a few occasional threads in the wall of Tubulina prefigure such a structure. To the genera of this order is appended the anomalous genus Lycogala, which seems to me better placed here than elsewhere.

TABLE OF GENERA OF LICEACEAE.

1. LICEA. Sporangia simple and regular or plasmodiocarp, gregarious; hypothallus none.

2. TUBULINA. Sporangia cylindric, or by mutual pressure becoming prismatic, distinct or more or less connate and aethalioid, seated upon a common hypothallus.

3. LYCOGALA. AEthalium with a firm membranaceous wall; from the inner surface of the wall proceed numerous slender tubules, which are intermingled with the spores.

I. LICEA, Schrad. Sporangia sessile, simple and regular or plasmodiocarp, gregarious, close or scattered; hypothallus none; the wall a thin, firm membrane, sometimes thickened with scales or granules, breaking up irregularly and falling away or dehiscent in a regular manner. Spores globose, variously colored.

The sporangia are not seated on a common hypothallus; they are, consequently, more or less irregularly scattered about on the substratum.

1. LICEA VARIABILIS, Schrad. Plasmodiocarp not much elongated, usually scattered, sometimes closer and confluent, somewhat depressed, the surface uneven or a little roughened and not shining, reddish-brown or blackish in color; the wall a thin, firm pellucid membrane, covered by a dense outer layer of thick brown or blackish scales, rupturing irregularly. Spores in mass pale ochraceous, globose or oval, even or nearly so, 13-16 mic. in diameter.

Growing on old wood. Plasmodiocarp 1-1.5 mm. in length, though sometimes confluent and longer. The wall is thick and rough, not at all shining. It is evidently the species of Schweinitz referred to by Fries under this name.

2. LICEA LINDHEIMERI, Berk. Sporangia sessile, regular, globose, gregarious, scattered or sometimes crowded, dark bay in color, smooth and shining; the wall a thin membrane with a yellow-brown outer layer, opaque, rupturing irregularly. Spores in mass bright bay, globose, minutely warted, opaque, 5-6 mic. in diameter.

Growing on herbaceous stems sent from Texas. Sporangia about .4 mm. in diameter. The bright bay mass of spores within will serve to distinguish the species. The thin brown wall appears dark bay with the inclosed spores.

3. LICEA BIFORIS, Morgan, n. sp. Sporangia regular, compressed, sessile on a narrow base, gregarious; the wall thin, firm, smooth, yellow-brown in color and nearly opaque, with minute scattered granules on the inner surface, at maturity opening along the upper edge into two equal parts, which remain persistent by the base. Spores yellow-brown in mass, globose or oval, even, 9-12 mic. in diameter. See Plate III, Fig. 1.

Growing on the inside bark of Liriodendron. Sporangia .25-.40 mm. in length, shaped exactly like a bivalve shell and opening in a similar manner. I have also received specimens of this curious species from Prof. J. Dearness, London, Canada.

4. LICEA PUSILLA, Schrad. Sporangia regular, sessile, hemispheric, the base depressed, gregarious, chestnut-brown, shining; the wall thin, smooth, dark-colored and nearly opaque, dehiscent at the apex into regular segments. Spores in the mass blackish-brown, globose, even, 16-18 mic. in diameter.

Growing on old wood, Sporangium about 1 mm. in diameter. On account of the color of the spores the genus Protoderma was created for this species by Rostafinski. It is number 2,316 of Schweinitz's N. A. Fungi.

II. TUBULINA, Pers. Sporangia cylindric, or by mutual pressure becoming prismatic, distinct or more or less connate and aethalioid, the apex convex, seated upon a common hypothallus; the wall a thin membrane, minutely granulose, firm and quite persistent, gradually breaking away from the apex downward. Spores abundant, globose, umber or olivaceous.

The sporangia usually stand erect in a single stratum, with their walls separate or grown together: in the more compact aethalioid forms, however, the sporangia, becoming elongated and flexuous, pass upward and outward in various directions, branching and anastomosing freely. See Plate III, Figs. 2, 3, 4.

1. TUBULINA CYLINDRICA, Bull. Sporangia cylindric, more or less elongated, closely crowded, distinct or connate, pale umber to rusty-brown in color, seated on a well developed hypothallus; the wall thin, firm, with minute veins and granules, semi-opaque, pale umber, often iridescent. Spores in mass pale umber to rusty-brown, globose, most of the surface reticulate, 6-8 mic. in diameter.

Growing on old wood, mosses, etc. AEthalium circular or irregular in shape, from one to several centimeters in extent, the individual sporangia 2-4 mm. in height. Plasmodium at first milky-white, soon changing to bright red, then to umber, becoming paler when mature and dry.

2. TUBULINA CASPARYI, Rost. Sporangia more or less elongated, closely crowded and prismatic, connate, pale umber to brown in color, seated on a conspicuous hypothallus; the wall thin, firm, minutely granulose, semi-opaque, pale umber, iridescent when well matured; all or many of the sporangia traversed by a central columella, from which a few narrow bands of the membrane stretch to the adjacent walls. Spores in the mass pale umber to brown, globose, the surface reticulate, 7-9 mic. in diameter.

Growing on old prostrate trunks. AEthalium two or three to several centimeters in extent, the individual sporangia 3-5 mm. in height. Plasmodium white, the immature sporangia dull-gray tinged with sienna color. The columella, with its radiating bits of membrane, is the same substance as the wall; it may be a reentrant edge of the prismatic sporangium, caused by excessive crowding together; at least, this may be regarded as its origin; there may have arisen some further adaptation. The species is Siphoptychium Casparyi, Rost. I am indebted to Dr. George A. Rex for the specimens I have examined.

3. TUBULINA CAESPITOSA, Peck. Sporangia short-cylindric, closely crowded, distinct or connate, argillaceous olive to olive-brown in color, seated on a well-developed hypothallus; the wall a thin membrane, with a dense layer of minute dark-colored round granules on the inner surface. Spores argillaceous olive in the mass, globose, minutely warted, 6-8 mic. in diameter.

Growing on old wood. AEthalium in irregular patches sometimes several centimeters in extent, the single sporangia about 1 mm. in height. Plasmodium dark olivaceous, the sporangia blackish if dried when immature, taking a paler shade of olivaceous, according to development and maturity. This is Perichaena caespitosa, Peck, in the 31st N. Y. Report.

III. LYCOGALA, Mich. AEthalium with a firm membranaceous wall; from the inner surface of the wall proceed numerous slender tubules, which are intermingled with the spores. The material of the wall appears under three different forms: the inner layer is a thin membrane, uniform in structure, of a yellow-brown color, and semi-pellucid; the outer layer consists of large flat roundish or irregular vesicles, brown in color, filled with minute granules, and arranged in one or more strata; from these vesicles originate the tubules, which traverse the wall for a certain distance, and then enter the interior among the spores; the tubules are more or less compressed, simple or branched, and the surface is ornamented with warts and ridges, which sometimes form irregular rings and reticulations.

If the sporophores in this genus be regarded as simple sporangia, which is the view that Rostafinski takes of one of the species, the tubules are simply the peculiar threads of a capillitium. If, however, the aethalium is a compound plasmodiocarp, the tubules stand for the original plasmodial strands and, consequently, represent the component sporangia.

1. LYCOGALA CONICUM, Pers. AEthalia small, ovoid-conic, gregarious, sometimes close together with the bases confluent, the surface pale umber or olivaceous marked with short brown lines, regularly dehiscent at the apex. The wall thin; the outer layer not continuous, the irregular brown vesicles disposed in angular patches and elongated bands, which have a somewhat reticulate arrangement. The tubules appear as a thin stratum upon the inner membrane; they do not branch, and they send long slender simple extremities inward among the spores. Spores in mass pale ochraceous, globose, minutely warted, 5-6 mic. in diameter. See Plate III, Fig. 5.

Growing on old wood. AEthalium 2-5 mm. in height, the tubules 3-8 mic. in thickness. This is Dermodium conicum of Rostafinski's monograph, but the structure is essentially the same as in the other species. Massee evidently did not have specimens of this species. I have never seen any branching of the tubules either in the wall or in the free extremities of the interior.

2. LYCOGALA EXIGUUM, Morg. n. sp. AEthalia small, globose, gregarious, the surface dark brown or blackish, minutely scaly, irregularly dehiscent. The wall thin; the vesicles with a dark polygonal outline, disposed in thin irregular reticulate patches, which are more or less confluent. The tubules appear as an interwoven fibrous stratum upon the inner membrane; they send long slender branched extremities inward among the spores. Spores in mass pale ochraceous, globose, nearly smooth, 5-6 mic. in diameter. See Plate III, Fig. 6.

Growing on old wood. AEthalium 2-5 mm. in diameter, the threads 2-10 mic. in thickness, with very slight thickenings of the membrane. The polygonal vesicles give a reticulate appearance to the dark-brown patches which ornament the surface of the wall.

3. LYCOGALA EPIDENDRUM, Buxb. AEthalia subglobose, gregarious, sometimes closely crowded and irregular, the surface umber, brown or olivaceous, minutely warted, at length, irregularly dehiscent at or about the apex. The wall thick, the brown vesicles loosely aggregated and densely agglutinated together, traversed in all directions by the much-branched tubules, which send long-branched extremities inward among the spores; the main branches thick and flat, with wide expansions, especially at the angles, the ultimate branchlets more slender and obtuse at the apex. Spores in the mass from pale to reddish ochre, globose, minutely warted, 5-6 mic. in diameter. See Plate III, Fig. 7.

Growing on old wood. AEthalium 5-12 mm. in diameter, the width of the tubules varying from 12-25 mic. in the main branches, with broader expansions at the angles, to 6-12 mic. in the more slender final branchlets. This is one of the most common of the Myxomycetes; it grows in all countries, and in this region may be found on old trunks at all seasons of the year.

4. LYCOGALA FLAVOFUSCUM, Ehr. AEthalia large, subglobose or somewhat pulvinate, solitary or gregarious, the surface at first silvery-shining, becoming yellow-brown, minutely areolate, irregularly dehiscent. The wall very thick and firm, hard and rigid; the thick outer layer of roundish brown vesicles closely compacted in numerous strata; from the vesicles of the lower strata the long and broad much-branched tubules proceed into the interior among the spores; the ultimate branchlets clavate and obtuse at the apex. Spores in the mass pale ochre, cinerous or brownish, globose, minutely warted, 5-6 mic. in diameter. See Plate III, Figs. 8, 9.

Growing on old trunks. AEthalium 1 to several centimeters in diameter, the width of the tubules varying from 25-60 mic. in the main branches, with sometimes much broader expansions at the angles, to 10-25 mic. in the ultimate branchlets. The brown vesicles of the outer wall are easily separated from each other and emptied of their contents by maceration; it is then seen that a thin pellucid membrane incloses numerous roundish granules, much resembling the spores, but usually a little larger, 5-8 mic. in diameter.



ORDER II.—RETICULARIACEAE.

Sporangia simple, regular and stipitate, or compound, forming an aethalium; the wall a thin membrane with distinct fibrous thickenings upon the inner surface, the membrane, or at least certain portions of it, disappearing usually at the maturity of the spores, leaving behind the more permanent fibrous thickenings as a more or less definite capillitium. Spores globose, purple, brown, ochraceous, rarely violaceous.

In this order the threads of a capillitium first make their appearance; but they are confined to the inner surface of the wall of the sporangium, being set at liberty by the early decay of the outer membrane.

TABLE OF GENERA OF RETICULARIACEAE.

a. AEthalia.

1. RETICULARIA. AEthalium composed of numerous slender sinuous sporangia which repeatedly branch and anastomose.

2. CLATHROPTYCHIUM. AEthalium composed of numerous regular erect sporangia.

b. Sporangia simple.

3. CRIBRARIA. Capillitium of slender threads combined into a network of polygonal meshes.

4. DICTYDIUM. Capillitium of numerous convergent ribs, which extend from base to apex, and are united by fine transverse fibers, thus forming a network of rectangular meshes.

I. RETICULARIA, Bull. AEthalium composed of numerous slender sinuous sporangia, which repeatedly branch and anastomose, closely packed together and seated upon a common hypothallus, the apices of the final branches coherent at the surface, and naked or covered by an additional corticate layer. Walls of the sporangia consisting of a thin membrane, with abundant fibrous thickenings, presenting broad expansions, narrowing to thin flat bands, and reduced in many places to slender fibrous threads. Spores abundant, globose, umber or violaceous.

After the maturity of the spores disintegration of the sporangial wall begins, the thin membrane disappearing more rapidly than the fibrous thickenings or the portions of the sporangial walls near the base, which are more compactly grown together; there is thus left at each stage an increasing number of the shreddy fibers mingled with the spores.

1. RETICULARIA SPLENDENS, Morg. n. sp. AEthalium pulvinate, circular or more or less elongated and irregular, seated on a conspicuous silvery hypothallus; the surface naked, bright umber, smooth and shining. Walls of the sporangia firm and quite persistent, pale umber, slowly disintegrating, consisting for the most part of wide expansions, with their angles tapering to narrow bands and slender threads. Spores in the mass pale umber, globose, most of the surface reticulate, 7-9 mic. in diameter. See Plate III, Fig. 10.

Growing on old wood. AEthalium from 1 to several centimeters in extent and 5-10 mm. in thickness, usually growing singly, rarely close enough to be confluent. This species has lately been referred to Reticularia rozeana, Rost., but it varies greatly from the account given of that species in the Journal of Botany for September, 1891.

2. RETICULARIA UMBRINA, Fr. AEthalium pulvinate, roundish, more or less irregular, the surface covered by a thin, silvery, shining, common cortex, which at the base is confluent with the hypothallus. Walls of the sporangia umber or rusty-brown next the base, with broad expansions in places thickly grown together, toward the surface passing into narrow bands and abundant fibrous threads, which rapidly disintegrate. Spores in the mass umber or rusty brown, globose, most of the surface reticulate, 7-9 mic. in diameter.

Growing on old trunks. AEthalium one to several centimeters in extent, and 5-15 mm. in thickness. The walls of the sporangia are much more reduced to the shreddy fibrous condition than in the preceding species, and on this account they much more rapidly disintegrate, causing the aethalium soon to collapse. It is Reticularia Lycoperdon, Bull.

3. RETICULARIA ATRA, A. & S. AEthalium pulvinate, variable in form and size, covered with a thin, fragile, blackish, cortical layer. Walls of the sporangia violaceous, next the base with broad expansions, in places more thickly grown together, toward the surface becoming narrow with more abundant fibrous threads, sometimes presenting a loose irregular network, the whole structure, however, quite variable, according to the stage of the disintegration. Spores globose, violet, minutely warted, 14-16 mic. in diameter.

Growing on wood and bark, especially of pine. AEthalium 2 or 3 to several centimeters in extent. This is Amaurochaete atra of Rostafinski's monograph, but the structure appears to be altogether similar to that of Reticularia umbrina.

II. CLATHROPTYCHIUM, Rost. AEthalium composed of numerous regular erect sporangia, seated in a single compact stratum, on a well-developed hypothallus, the surface formed by the coherent apices. Sporangia at first cylindric, with the apex convex and the wall entire; soon, by mutual pressure, they become prismatic and the lateral faces disappear, leaving the edges and the apex permanent. Spores globose, ochraceous.

1. CLATHROPTYCHIUM RUGULOSUM, Wallr. AEthalium composed of numerous very slender sporangia, closely compacted into a single stratum, and seated on a conspicuous silvery hypothallus; the surface ochroleucous, honey color or olivaceous. The sporangia are typically hexangular when the lateral faces disappear, leaving at the edges six simple triangular threads, extending from the angles of the hexagonal apex downward to the base. Spores in the mass ochraceous, yellowish or brownish, globose, minutely warted, 8-10 mic. in diameter.

Growing on old wood. AEthalium somewhat circular, or often quite irregular in shape, 1 to several centimeters in extent, the individual sporangia nearly 1 mm. in height, but scarcely .1 mm. in thickness. Deviations from the typical form of the sporangia sometimes occur, they are not seldom pentangular, and I have seen the apices quadrangular, with only four threads, or even triangular, and with but three; the threads, too, are said occasionally to branch and anastomose. Reticularia plumbea, Fries, S. M. III, 88; and Ostracoderma spadiceum, Schw., N. A. Fungi No. 2,381.

III. CRIBRARIA, Pers. Sporangia simple, globose or obovoid, stipitate, often cernuous; the wall regularly thickened on the inner surface in two ways, the lower basal portion by radiating ribs consisting of minute brown granules, the upper part by slender threads combined into a network of polygonal meshes; the basal portion of the membrane is commonly persistent with its thickening and is called the calyculus, the upper part nearly always disappears from the network at maturity; there are usually nodules of the brown granules at the angles of the network. Spores globose, purple, brown, ochraceous.

a. Sporangium, large.

1. CRIBRARIA ARGILLACEA, Pers. Sporangia globose or obovoid, stipitate or nearly sessile, standing close together on a thin and evanescent hypothallus; the wall quite firm, silvery-shining, the greater portion persistent, breaking away about the apex; calyculus small, the brown radiating ribs soon passing into a network of polygonal meshes, the threads with irregular granulose-thickened portions at intervals throughout their whole extent. Stipe very short, erect, brown. Spores in the mass argillaceous, globose, 5-7 mic. in diameter.

Growing in large irregular patches on rotten trunks. Sporangia .6-.8 mm. in diameter, the stipe always much shorter than the sporangium, sometimes nearly obsolete. The resemblance of this species to some forms of Tubulina caespitosa is very great.

2. CRIBRARIA VULGARIS, Schrad. Sporangium large, globose, stipitate, somewhat cernuous; the calyculus brown, finely ribbed and granulose within, occupying but a small part of the sporangium; the network of slender threads, with very small nodules at the angles, each with several (3-7) radiating threads, sometimes with one or two free extremities, the meshes triangular or rhombic. Stipe rather short, stout, tapering upward, usually a little bent or curved at the apex, dark purplish brown in color. Spores in the mass pale ochraceous, globose, even, 5-7 mic. in diameter.

Growing on old wood. Sporangium .5-.7 mm. in diameter, the stipe two or three times the diameter of the sporangium in length. Recognized by the large sporangium and the very small nodules with their few radiating threads.

3. CRIBRARIA DICTYDIOIDES, C. & B. Sporangium large, globose, stipitate, cernuous; the calyculus small, with thickish brown ribs, from which the outer thin membrane often disappears soon after maturity; the network of slender threads, with large brown nodules at the angles, more or less elongated and irregular in shape, each with numerous (5-15) radiating threads, usually some with free extremities, the meshes largely triangular. Stipe long, tapering upward, flexuous, curved at the apex, dark purplish-brown in color. Spores in mass pale ochraceous, globose, even, 5-7 mic. in diameter.

Growing on rotten wood, especially of oak. Sporangium .5-.6 mm. in diameter, the stipe from three to five times as long. This species appears to be intermediate between Cribraria vulgaris and Cribraria intricata; the nodules are usually large and irregular, but the characteristic parallel threads of C. intricata do not often occur. The outer membrane of the calyculus is by no means always absent.

4. CRIBRARIA ELEGANS, B. & C. Sporangium rather large, globose, stipitate, somewhat cernuous; the calyculus thickly coated inside with dark purple granules, faintly ribbed, occupying about a third part of the sporangium; the network of slender threads, with large irregular dark purple nodules, quite variable in shape and size, angular and lobed, below sometimes much elongated, the meshes very irregular. Stipe rather short, tapering upward, bent at the apex, dark purple in color. Spores in the mass bright purple, globose, even, 5-7 mic. in diameter.

Growing on old wood. Sporangium .4-.5 mm. in diameter, the stipe two or three times as long. It does not appear to be greatly different from Cribraria purpurea, Schrad.

b. Sporangium, small.

5. CRIBRARIA TENELLA, Schrad. Sporangium small, globose, stipitate, cernuous; the calyculus brown, shining, granulose within and faintly ribbed, occupying from one-fourth to one-half the sporangium, sometimes the outer thin membrane early disappearing; the network of slender threads with small roundish or irregular nodules at the angles, each with several (4-8) radiating threads, sometimes two or three with free extremities, the meshes triangular or rhombic. Stipe long, tapering upward, flexuous, curved at the apex, purplish-brown in color. Spores pale ochraceous in mass, globose, even, 5-7 mic. in diameter.

Growing on old wood. The sporangium .3-.4 mm. in diameter, the stipe three to five times as long. This is a much more delicate species than Cribraria dictydioides. The calyculus is variable in size; in some examples the thin connecting membrane between the ribs has disappeared.

6. CRIBRARIA MICROCARPA, Schrad. Sporangium very small, globose, stipitate, somewhat cernuous; the calyculus represented by a few short brown ribs, the outer membrane soon disappearing; the network of slender threads, with small roundish nodules at the angles, each with several (4-6) radiating threads, with an occasional free extremity, the meshes largely rhombic. Stipe very long, slender, somewhat flexuous, bent at the apex, purplish-brown in color. Spores in mass pale ochraceous, globose, even, 6-7 mic. in diameter.

Growing on old wood. Sporangium .22-.27 mm. in diameter, the stipes 1-2 mm. in length. Readily distinguished by its very small sporangium and the comparatively very long stem. I am indebted to Dr. George A. Rex for specimens of this species.

7. CRIBRARIA CUPREA, Morg. n. sp. Sporangium very small, oval or somewhat obovoid, stipitate, cernuous; the calyculus copper-colored, finely ribbed and granulose within, occupying from one-third to one-half the sporangium; the network of slender threads, with rather large triangular or quadrilateral meshes, and with large irregular dark copper-colored nodules, each having several (4-7) radiating threads, with an occasional free extremity. Stipe not very long, tapering upward, curved at the apex, of the same color as the sporangium or darker below. Spores pale coppery in mass, globose, even, 6-7 mic. in diameter. See Plate III, Fig. 11.

Growing on old wood. Sporangium .30-.35 X .25-.30 mm, the stipe two to four times as long as the sporangium. A minute species, easily recognized by its almost uniform color of bright new copper.

IV. DICTYDIUM, Schrad. Sporangium simple, depressed-globose, stipitate, cernuous; the wall regularly thickened on the inner surface by numerous convergent ribs, which extend from base to apex and are united by fine transverse fibers, thus forming a network of rectangular meshes; the basal portion of the membrane sometimes persists as a calyculus, the upper part disappears at maturity. Spores globose; purplish.

The ribs run from base to apex like the meridians on a globe; they are simple, or here and there they separate into two divergent branches, which sometimes again converge into one; at the apex of the sporangium there is usually a small irregular net in which all the ribs terminate.

1. DICTYDIUM CERNUUM, Pers. Sporangium depressed-globose, umbilicate at the apex, stipitate, cernuous, purplish-brown in color; the calyculus granulose within, occupying from one-fourth to one-third of the sporangium, the ribs united by firm, persistent fibers. Stipe not very long, erect, tapering upward, bent at the apex, purplish-brown, the apex pale and pellucid, standing on a small hypothallus. Spores purplish-brown in mass, globose, even, 5-7 mic. in diameter.

Growing on old wood. Sporangium .4-.5 mm. in diameter, the stipe two or three times longer than the diameter of the sporangium. This appears to be the species figured and described by Rostafinski and by Massee.

2. DICTYDIUM LONGIPES, Morg. n. sp. Sporangium large, depressed-globose, the apex umbilicate, stipitate, cernuous, dark purple in color; calyculus usually wholly wanting, the ribs united by weak fibers, which are easily torn asunder, allowing the ribs to curl up inwards. Stipe very long, flexuous, tapering upward, curved and twisted at the apex, dark purple in color, standing on a thin hypothallus. Spores in the mass dark purple, globose, even, 5-7 mic. in diameter. See Plate III, Fig. 12.

Growing on rotten wood, mosses, etc. Sporangium .5-.7 mm. in diameter, the stipe three to five times as long. This is a much larger species than the preceding; it has a uniform dark purple hue, the stipe is very long and much bent and twisted, the ribs of the sporangium are soon torn apart and rolled inward.

EXPLANATION OF PLATE III

Fig. 1.—Licea biforis, Morgan, n. sp.

Figs. 2, 3, 4.—Diagrammatic representation of the structure of Tubulina

Fig. 5.—Lycogala conicum, Pers., natural size

Fig. 6.—Lycogala exiguum, Morgan, n. sp., natural size

Fig. 7.—Lycogala epidendrum, Buxb., natural size

Fig. 8.—Lycogala flavofuscum, Ehr., natural size

Fig. 9.—Portion of tubule of Lycogala flavofuscum

Fig. 10.—Reticularia splendens, Morgan, n. sp., natural size

Fig. 11.—Cribraria cuprea, Morgan, n. sp.

Fig. 12.—Dictydium longipes, Morgan, n. sp.



* * * * *

From the Journal of the Cincinnati Society of Natural History, April, 1893.

THE MYXOMYCETES OF THE MIAMI VALLEY, OHIO.

BY A. P. MORGAN.

Second Paper.

(Read May 2, 1893.)



ORDER III. PERICHAENACEAE.

Sporangia sessile or plasmodiocarp; the wall a thin membrane, with a more or less thickened outer layer of minute brownish scales and granules. Capillitium of long and very slender tubules, proceeding from numerous points of the sporangial wall, loosely branched, forming no evident network, the surface minutely warted or spinulose. Spores globose, oval, or somewhat irregular, yellow.

The order is distinguished by the sessile sporangia, with thick brown walls, and the very slender threads of the capillitium, with irregular and indefinite markings.

TABLE OF GENERA OF PERICHAENACEAE.

1. PERICHAENA. Sporangia more or less depressed, roundish or more commonly polygonal and irregular, dehiscent in a circumscissile manner.

2. OPHIOTHECA. Plasmodiocarp terete and more or less elongated, bent and flexuous, sometimes annular or reticulate, irregularly dehiscent.

I. PERICHAENA, Fr. Sporangia more or less depressed, roundish or more commonly polygonal and irregular, the edges approximate and sometimes confluent; the wall a thin membrane, with a thick dense yellow-brown outer layer of minute scales and granules, becoming darker at the surface, dehiscent in a circumscissile manner. Capillitium of very slender loosely-branched threads, with the surface minutely warted. Spores globose, oval or somewhat irregular, yellow.

Distinguished from Ophiotheca by the flattened sporangium with a regular circumscissile dehiscence.

1. PERICHAENA DEPRESSA, Lib. Sporangia very much depressed, polygonal, irregular, crowded, the edges contiguous, sometimes confluent; the wall thick, yellow-brown within and scarcely impressed by the spores; the outer surface smooth, brown-red to brown or blackish in color, dehiscent in a circumscissile manner. Capillitium of slender loosely-branched threads, 1-3 mic. in thickness, the surface merely uneven or very minutely warted. Spores globose, yellow, 9-10 mic. in diameter. See Plate I, Fig. 13.

Growing on the inside of the bark of Juglans, Acer, etc. Sporangia variable in size, 7-1.3 mm. in breadth, irregular and angular, much flattened. It is said to include Perichaena vaporaria, Schw.

2. PERICHAENA IRREGULARIS, B. & C. Sporangia depressed, irregular, polygonal, crowded, the edges contiguous and sometimes confluent; the wall thick, yellow inside and faintly reticulately impressed by the spores, the outer surface smooth, purplish-brown, dehiscent in a circumscissile manner. Capillitium of slender-loosely branched threads, about 2 mic. in thickness, the surface minutely warted or spinulose. Spores subglobose, yellow, 9-10 mic. in diameter.

Growing on the outer bark of Acer, etc. Sporangium .5-.6 mm. in width, closely crowded and irregular. It is much smaller than Perichaena depressa, and its threads are more distinctly warted and spinulose.

3. PERICHAENA CORTICALIS, Batsch. Sporangia globose, the base depressed, gregarious: the wall thick, yellow within and distinctly reticulately impressed by the spores, the outer surface reddish-brown or yellow-brown in color, dehiscent in a circumscissile manner. Capillitium of slender loosely-branched threads, about 2 mic. in thickness, the surface very minutely warted. Spores subglobose, yellow, 10-12 mic. in diameter.

Growing on the inside of the bark of Elm. Sporangia .5-.6 mm. in diameter, quite regular in shape, with a slightly flattened base. My specimens are from Prof. McBride, of Iowa.

4. PERICHAENA MARGINATA, Schw. Sporangia depressed, polygonal, approximate and sometimes confluent, the surface cinereous-pulverulent, seated on a silvery hypothallus; the wall firm, thick, the outer surface yellow-brown, covered with minute whitish scales, the inner surface yellow, deeply reticulately impressed by the spores which rest against it, dehiscent in a circumscissile manner. Capillitium consisting of a few simple or somewhat branched threads or well-nigh obsolete. Spores subglobose, yellow, 12-14 mic. in diameter.

Growing on the outer surface of the bark of Acer, Fagus, etc. Sporangia .4-.6 mm. in width. This is plainly Perichaena cano-flavescens, Raunkier. I do not find any threads of a capillitium in my specimens.

II. OPHIOTHECA, Currey. Plasmodiocarp terete and more or less elongated, bent and flexuous, sometimes annular or reticulate, the surface not polished or shining: the wall a thin membrane, with a thin outer layer of minute scales and granules, irregularly dehiscent. Capillitium of very slender loosely-branched threads, with the surface minutely warted and spinulose. Spores globose, oval or somewhat irregular, yellow.

Distinguished from Perichaena by the terete plasmodiocarp and by the more spinulose capillitium. Cornuvia of Rostafinski.

1. OPHIOTHECA CHRYSOSPERMA, Currey. Plasmodiocarp globose or oblong to elongated, and bent or flexuous, sometimes annular or branched and reticulate, dull brown in color; the wall a thin yellowish membrane, with a thin yellow-brown outer layer, irregularly dehiscent. Capillitium of slender loosely-branched threads, 2-3 mic. in thickness, the surface minutely spinulose. Spores subglobose, yellow, 8-9 mic. in diameter.

Growing on the inner surface of old bark of Quercus, etc. Plasmodiocarp .4-.5 mm. in thickness, variable in length. Cornuvia circumscissa of Rostafinski's monograph.

2. OPHIOTHECA WRIGHTII, B. & C. Plasmodiocarp more or less elongated, bent and flexuous, very commonly in small rings, from brownish-ochre to brown or blackish in color, not polished; the wall a thin yellow membrane, with a thin brown outer layer, irregularly dehiscent. Capillitium of slender loosely-branched threads, 2-3 mic. in thickness, furnished with numerous straight or bent long-pointed spinules. Spores subglobose, yellow, minutely warted, 10-12 mic. in diameter. See Plate I, Fig. 14.

Growing on the inside of bark of Acer, Carya, etc. Plasmodiocarp about .5 mm. in thickness, variable in length, often in small rings 1-2 mm. in diameter. The prickly threads are quite characteristic; the spinules are 3-5 mic. in length. Hemiarcyria melanopeziza, Speg., is evidently the same thing.

3. OPHIOTHECA VERMICULARIS, Schw. Plasmodiocarp terete and more or less elongated, bent and flexuous, sometimes annular or reticulate, the surface not polished, brownish in color; the wall a thin yellow membrane, covered on the outside by a more or less thickened brown layer of scales and granules, irregularly dehiscent. Capillitium of slender loosely branched threads, 2-3 mic. in thickness, the surface with minute warts and ridges. Spores subglobose, yellow, 10-12 mic. in diameter.

Growing on the inside of old bark. Plasmodiocarp about .4 mm. in thickness and various in length; in my specimens the sporangia are mostly small rings. The species looks exactly like Ophiotheca Wrightii, but the character of the threads is quite different.

4. OPHIOTHECA PALLIDA, B. & C. Plasmodiocarp terete, oblong or elongated annular and flexuous, the surface dull, pale ochraceous; the wall a thin pellucid membrane, minutely granulate, with a thin pale ochraceous outer layer, irregularly dehiscent. Capillitium of slender loosely-branched threads, 2-3 mic. in thickness, the surface minutely warted or spinulose. Spores subglobose, pale yellow, 10-12 mic. in diameter.

Growing on dead stems of herbaceous plants. Plasmodiocarp .3-.4 mm. in thickness, variable in length, sometimes short and roundish or oblong, sometimes much elongated and flexuous. More delicate than Ophiotheca vermicularis, and distinguished by its pallid color throughout.



ORDER IV. ARCYRIACEAE.

Sporangia regular and stipitate, rarely sessile; the wall a thin membrane, minutely granulose, colored as the spores and capillitium, the upper part soon torn away in a somewhat circumscissile manner, and early disappearing. Capillitium of slender tubules, repeatedly branching and anastomosing to form a complicated network of evident meshes, more or less expanded after dehiscence; the surface of the threads minutely warted or spinulose or with elevated ridges in the shape of rings, half rings or reticulations.

This order is specially distinguished by the threads of the capillitium forming a complicated network of evident meshes.

TABLE OF GENERA OF ARCYRIACEAE.

1. LACHNOBOLUS. Capillitium of slender tubules, quite variable in thickness, proceeding from numerous points of the sporangial wall.

2. ARCYRIA. Capillitium of slender tubules, issuing from the interior of the stipe, the network without any free extremities.

3. HETEROTRICHIA. Capillitium issuing from the interior of the stipe, the peripheral portion of the network bearing numerous short acute free branches.

I. LACHNOBOLUS, Fr. Sporangia stipitate or sessile, the wall a thin delicate membrane, minutely granulose, rupturing irregularly. Stipe short or sometimes wanting. Capillitium of slender tubules quite variable in thickness, proceeding from numerous points of the sporangial wall and forming a complicated network, the surface minutely warted or spinulose. Spores globose, yellowish or flesh-color.

This genus differs from Arcyria in the capillitium springing from numerous points of the sporangial wall.

1. LACHNOBOLUS GLOBOSUS, Schw. Sporangia globose, stipitate, pale yellow, changing to clay-color; the wall thin and delicate, pellucid, minutely granulose, the upper part torn away and soon disappearing, the lower half more persistent. Stipe short, tapering upward, expanding at the base into a small hypothallus. Capillitium arising from the lower portion of the sporangium, forming a complicated network, the threads 3-5 mic. in thickness, the surface closely covered with minute warts. Spores globose, pale yellow to clay-color in mass, 8-9 mic. in diameter. See Plate I, Fig. 15.

Growing on the spines of Chestnut burs. Sporangia .5-.6 mm. in diameter, the stipe shorter than the sporangium.

2. LACHNOBOLUS INCARNATUS, A. & S. Sporangia globose or ellipsoidal, substipitate, closely crowded and seated on a common hypothallus; the wall thin and delicate, pellucid, minutely granulose, dehiscing irregularly. Stipe very short or often obsolete. Capillitium proceeding from the inner surface of the sporangial wall, forming a complicated network, the threads extremely variable in thickness, minutely warted and spinulose. Spores globose, flesh-color in the mass, 8-9 mic. in diameter.

Growing on old wood. Sporangia .5-.8 mm. in height, sessile on a narrow base or with a very short stipe; the threads of the capillitium are generally 3-5 mic. in thickness, but there are broader expansions at the nodes and elsewhere. My specimens are from Prof. McBride, of Iowa. The species is extremely variable, and these specimens differ much from those described elsewhere.

II. ARCYRIA, Hill. Sporangia regular ovoid to cylindric, stipitate; the wall a thin delicate membrane, circumscissile or torn away near the base, the upper portion evanescent, the lower part persistent, small and cup-shaped. Stipe more or less elongated, the interior containing roundish vesicles which become smaller upward, and gradually pass into the normal spores. Capillitium of slender tubules, issuing from the interior of the stipe, forming a complicated network, without any free extremities, the surface minutely warted or spinulose or with annular ridges. Spores globose, red, brown, yellow, cinereous.

Sec.1. CLATHROIDES, Mich. Capillitium closely attached by a few threads which issue from the interior of the stipe, and are free from the calyculus (except in A. punicea), much elongated after dehiscence, weak and drooping or prostrate; the meshes open and irregular, not differing externally and internally, their threads similar throughout, the warts or ridges of the surface exhibiting a spiral arrangement.

1. ARCYRIA PUNICEA, Pers. Sporangium ovoid, more or less elongated; the calyculus small, plicate-sulcate. Stipe long, erect, brownish-red in color, expanded at the base into a small hypothallus. Capillitium firmly attached by numerous threads which are connate with the wall of the calyculus, much elongated after dehiscence, ovoid-oblong to cylindric, bright red in color, fading to red-brown or brownish-ochre; the threads uniform in thickness, about 3 mic., the surface with a series of prominent half-rings, which wind around the thread in a long spiral. Spores globose, even, 6-8 mic. in diameter.

Growing on old bark, wood, mosses, etc. The stipe 1-2 mm. in length, the capillitium elongated 2-4 mm. The commonest of the species, conspicuous by reason of its bright red color.

2. ARCYRIA MINOR, Schw. Sporangium ovoid-oblong; the calyculus small, sulcate and ribbed, granulose. Stipe short, erect, brownish-red in color, standing on a thin hypothallus. Capillitium much elongated after dehiscence, oblong to cylindric, lax and prostrate, bright red to brownish in color; the threads uniform in thickness, 2.5-3 mic., the surface with a series of prominent half-rings, which wind around the thread in a long spiral. Spores globose, even, 7-9 mic. in diameter. See Plate I, Fig. 17.

Growing on old wood, bark, Polyporus, etc. The stipe .4-.7 mm. in length, the capillitium elongated 1.5-3 mm. Not uncommon, but it is usually referred to A. adnata.

3. ARCYRIA ADNATA, Batsch. Sporangium ovoid; the calyculus very small, finely ribbed and granulose. Stipe very short or entirely wanting. Capillitium much expanded after dehiscence, globose or obovoid, pale red to brownish in color; the threads uniform in thickness, about 4 mic., the surface with a series of prominent half-rings with mingled warts and spines, which wind around the thread in a long spiral. Spores globose, even, 6-8 mic. in diameter.

Growing in small clusters on old wood. A small species, the capillitium expanded 1-2 mm., the stipe extremely short, or altogether absent.

4. ARCYRIA NUTANS, Bull. Sporangium cylindric; the calyculus small, granulose, ribbed and sulcate. Stipe very short, arising from a common hypothallus. Capillitium greatly elongated after dehiscence, cylindric, drooping and pendulous, pale yellow or pale ochraceous; the threads 3-4 mic. in thickness, the surface covered with spinules, among which are rings and half-rings, with an indistinct spiral arrangement. Spores globose, even, 7-9 mic. in diameter.

Growing on old wood. The capillitium elongated 4-8 mm., the stipe very short. A very conspicuous species by reason of its long pale yellow capillitium.

Sec.2. PLECTANELLA. Capillitium erect, firmly attached by numerous threads, which issue from the interior of the stipe, but are connate with the wall of the calyculus, after dehiscence not much expanded: the meshes at the surface of the network much smaller than those within, folded back and forth, narrow and irregular, their threads densely warted or spinulose; the meshes of the interior much larger, open and expanded, their threads with minute scattered warts or perfectly smooth.

5. ARCYRIA CINEREA, Bull. Sporangium ovoid or oblong-ovoid; the calyculus very small. Stipe long, erect, cinereous, becoming blackish, standing on a thin hypothallus. Capillitium not much expanded after dehiscence, ovoid-oblong, erect, pale cinereous, sometimes pale yellowish; the external threads densely spinulose, 2-3 mic. in thickness; the threads of the interior thicker, 3-5 mic., and very minutely warted or quite smooth. Spores globose, even, 6-8 mic. in diameter.

Growing on old wood. Capillitium 1-2 mm. long, the stipe about the same length.

6. ARCYRIA COOKEI, Mass. Sporangium ovoid-cylindric, the calyculus very small. Stipe long, erect, gray to mouse-color, darker below, arising from a thin hypothallus. Capillitium not much expanded after dehiscence, ovoid-cylindric, erect, gray to mouse-color; the superficial threads densely and uniformly covered with minute warts, 3-5 mic. in thickness; the threads of the interior thinner, about 2 mic. and smooth, or with very minute scattered warts. Spores globose, even, 6-8 mic. in diameter. See Plate I, Fig. 16.

Growing on old wood, mosses, etc. Capillitium 1-2 mm. long, the stipe about the same length. It seems as common as Arcyria cinerea, and has heretofore been included in it. See Massee's Monograph, p. 154.

7. ARCYRIA DIGITATA, Schw. Sporangium cylindric, the calyculus very small. Stipe long, ascending, brownish in color, usually several fasciculate or to some extent connate, the sporangia divergent at the apex. Capillitium not much expanded after dehiscence, cylindric, pale cinereous, or pale yellowish; the threads variable in thickness. 2-4 mic., those at the surface densely and minutely warted, those of the interior nearly smooth. Spores globose, even, 6-8 mic. in diameter.

Growing on old wood. Capillitium 2-4 mm. long, the stipe about the same length. Arcyria bicolor, B. & C.

III. HETEROTRICHIA, Massee. Sporangia regular, oblong-ovoid, stipitate; the wall a thin delicate membrane, the upper part disappearing at maturity, leaving the basal portion as a small calyculus. Stipe filled with large thick-walled vesicles, which are sub-angular from mutual pressure; these become smaller upward, and pass gradually into normal spores. Capillitium issuing from the interior of the stipe, the central and superficial threads dissimilar, forming a complicated network, with numerous free extremities, the surface minutely warted, or with annular ridges. Spores globose, brownish.

Distinguished from Arcyria by the numerous free extremities of the peripheral portion of the network.

1. HETEROTRICHIA GABRIELLAE, Massee. Sporangium oblong-ovoid, stipitate; the calyculus small, thin, smooth. Stipe very short, erect, yellowish-brown in color. Capillitium much elongated after dehiscence, cylindric-ovoid, sub-erect; the threads of the central portion about 1.5 mic. thick, with slightly elevated ridges partly encircling the tube, nearly colorless; threads of the peripheral portion bright yellow, 5-6 mic. thick, with numerous short acute free branches, the surface densely and minutely warted. Spores in mass, yellowish-brown, globose, even, 7-8 mic. in diameter. See Plate I, Fig. 18.

Growing on wood; S. Carolina, H. W. Ravenel. The sporangia densely crowded, becoming scattered toward the margin of the cluster. Massee's Monograph of the Myxogasters.



ORDER V. TRICHIACEAE.

Sporangium regular and stipitate or sessile, rarely plasmodiocarp; the wall a thin membrane, usually granular or venulose on the inner surface, colored as the spores and capillitium, irregularly dehiscent. Capillitium of slender tubules, simple or branched, scarcely forming an evident network; the surface of the threads furnished with continuous ridges, which wind around the tube in a spiral manner. Spores globose, red, brown, yellow, olivaceous.

This order is readily recognized by the spiral ridges which wind around the tubules of the capillitium.

TABLE OF GENERA OF TRICHIACEAE.

1. HEMIARCYRIA. Capillitium of long slender tubules, arising from the base of the sporangium, or issuing from the interior of the stipe; the spiral ridges parallel and conspicuous.

2. CALONEMA. Capillitium of slender tubules, arising from the base of the sporangium; the surface traversed by a system of branching veins.

3. TRICHIA. Capillitium consisting of numerous short slender tubules, called elaters, which are wholly free; the spiral ridges parallel and conspicuous.

4. OLIGONEMA. Capillitium scanty, composed of elaters habitually irregular and abnormal; the surface variously marked.

I. HEMIARCYRIA, Fr. Sporangia regular and stipitate, rarely plasmodiocarp, the wall at maturity breaking away from above downward, leaving more or less of the lower portion persistent. Stipe more or less elongated, rarely wanting, resting on a thin hypothallus. Capillitium of long slender tubules, more or less branched, arising from the base of the sporangium, or issuing from the interior of the stipe; the spiral ridges parallel and conspicuous, 3-5, rarely more in number, smooth or spinulose. Spores globose, red, yellow.

The genus is related on the one hand to Arcyria by the mode of attachment of the threads, on the other hand to Trichia, by the parallel spiral ridges which wind around them. By the mode of branching of the threads, the species fall readily into two sections.

Sec.1. ARCYRIOIDES. Capillitium of slender threads, branching and anastomosing, thus forming a more or less evident network.

In some of the species the large irregular meshes of the network are scarcely to be discerned, but are rather to be inferred from the abundant branching of the threads and the paucity of the free extremities.

1. HEMIARCYRIA PLUMOSA, Morgan, n. sp. Sporangium obovoid to turbinate, olive-yellow to olive-brown in color, stipitate; the wall densely granulose within, externally smooth and shining, the upper part soon disappearing, leaving a funnel-shaped persistent base. Stipe long, erect, reddish-brown, arising from a thin hypothallus. Capillitium of threads 5-7 mic. in thickness, repeatedly branched and anastomosing, to form a dense network without any free extremities, olive-yellow to olive-brown in color; the spiral ridges five or six, close, smooth. Spores in mass, lemon-yellow, globose, very minutely warted, 8-9 mic. in diameter. See Plate I, Fig. 19.

Growing gregariously on old damp logs; very common in this region. Sporangium with the stipe 2-3 mm. in height, the stipe usually much longer than the sporangium; the capillitium expands considerably after the disappearance of the upper part of the sporangium. This species is an Arcyria in every respect, except the spiral ridges, which wind about the thread of the capillitium.

2. HEMIARCYRIA VARNEYI, Rex. Sporangium elongated ovoid, pale yellow, stipitate; the upper part of the wall disappearing at maturity, leaving a small cup-shaped persistent base. Stipe very short, dull brown. Capillitium of very slender threads 3.2-3.5 mic. in thickness, dull ochre in color, forming a network of small meshes, with numerous short slightly clavate free extremities, which proceed from the peripheral meshes; the spiral ridges seven or eight, winding unevenly, those of the superficial threads minutely spinulose. Spores in mass pale yellow, globose, even, 6-7 mic. in diameter.

Growing on old wood; Kansas, May Varney. Sporangium with the stipe about 1 mm. in height, the stipe very short. Dr. Rex, in Proceedings of the Academy of Natural Sciences, Philadelphia, 1891.

3. HEMIARCYRIA ABLATA, Morgan n. sp. Sporangium obovoid to turbinate, yellow or olive-yellow, stipitate; the wall rather firm, smooth and shining, breaking away about the apex, leaving the greater portion persistent. Stipe short, erect, yellow-brown to blackish in color, arising from a thin hypothallus. Capillitium of threads, 5-7 mic. in thickness, yellowish-ochre in color, more or less branched; the free extremities very scarce, obtuse or slightly swollen; the spiral ridges four or five, close, smooth or very minutely warted. Spores in mass, yellow, globose, minutely warted, 8-9 mic. in diameter.

Growing on old wood of Elm, etc. Sporangium with the stipe 1.5-2.5 mm. in height, the stipe variable in length, but not longer than the sporangium, diameter of the sporangium .6-.8 mm. A half dozen threads proceed from the inner wall of the stipe branch twenty-five or thirty times, and afford scarcely half a dozen free ends.

4. HEMIARCYRIA STIPATA, Schw. Sporangia terete, elongated and flexuous, closely packed together and lying upon one another, stipitate, from bright incarnate to brick red or bay in color, smooth and shining; the wall thin and fragile, soon disappearing, except a small cup-shaped portion at the base. The stipes very short, often entirely concealed by the dense mass of sporangia, arising from a common hypothallus. Capillitium of threads somewhat variable in thickness, 3-6 mic., repeatedly branched and forming a network of very unequal meshes, with occasional clavate free extremities, pale to dark red in color; the spiral ridges three or four, often irregular, thickened or interrupted by minute warts and spinules. Spores in mass incarnate to brownish-red, globose, even, 7-9 mic. in diameter.

Growing on old wood of Liriodendron. Sporangia usually in small patches, each 1-2 mic. in length, the stipe very thin and short.

Sec.2. HEMITRICHIA. Capillitium of very long slender threads, simple or remotely branched, and not forming a network, their further extremities all free.

The threads of the capillitium in these species are usually much coiled and entangled, but when straightened out they are seen to be very long, but few in number, fixed at one end and free at the other.

5. HEMIARCYRIA LONGIFILA, Rex. Sporangium obovoid or pyriform, yellow, stipitate; the wall a thin pellucid membrane, smooth and shining, beautifully iridescent, breaking away above the middle, the lower cup-shaped portion persistent. Stipe very short, reddish-brown to blackish, arising from a common hypothallus. Capillitium of slender threads, 3.5-4 mic. in thickness, golden yellow in color, simple or very rarely branched; the free extremities obtuse or slightly swollen, sometimes minutely apiculate; the spiral ridges, three or four, rather distant, with very minute scattered spinules or nearly smooth. Spores in mass, golden-yellow, globose, minutely warted, 9-10 mic. in diameter.

Growing on old wood of Oak, etc. Sporangium with the stipe .8-1.5 mm. in height, the stipe very short, not exceeding the diameter of the sporangium. A small species, distinguished by its golden-yellow spores and capillitium.

6. HEMIARCYRIA FUNALIS, Morgan n. sp. Sporangium obovoid to turbinate, yellow or olive yellow, polished stipitate; the wall firm, thickened on the inner surface by an olivaceous layer, breaking away from above downward, leaving an irregular cup-shaped base. Stipe short, reddish-brown to blackish, arising from a thin hypothallus. Capillitium of threads 6-8 mic. in thickness, yellowish-ochre or dull ochre in color, simple or remotely branched; the free extremities obtuse or swollen; the spiral ridges four or five, minutely warted. Spores in mass yellow, globose, minutely warted, 8-9 mic. in diameter. See Plate I, Fig. 20.

Growing on old wood. Sporangium 1.5-2.5 mm. in height, the stipe variable, but usually much shorter than the sporangium. Scarcely to be distinguished from Hemiarcyria ablata, except by the threads of the capillitium.

7. HEMIARCYRIA RUBIFORMIS, Pers. Sporangium obovoid or turbinate to cylindric, usually few to many fasciculate upon the united stipes, sometimes sessile, brown-red to brown or blackish in color, smooth and often shining with a metallic luster; the wall much thickened by a dense brownish-red layer of minute granules, at maturity the apex torn away, leaving much the greater part persistent. Capillitium of slender threads, 4-6 mic. in thickness, brownish-red in color, very rarely branched; the free extremities usually terminated by a stout spine; the spiral ridges three or four, furnished with numerous spinules. Spores in mass, brownish-red, globose, minutely warted, 9-11 mic. in diameter.

Growing on old wood; one of the commonest of the Myxomycetes. The fascicle 3-4 mm. in height, the individual sporangia .5-.6 mm. in diameter.

8. HEMIARCYRIA SERPULA, Scop. Plasmodiocarp terete, flexuous, usually branching and anastomosing to form an extensive network, from tawny to golden-yellow in color; the wall thin above and yellow, breaking open irregularly and falling away down to the brownish thicker adherent base. Capillitium consisting of a few long slender threads with numerous scattered short branches, the threads 4-6 mic. in thickness, golden-yellow; the free ends of the branches terminating in a slender spine; the spiral ridges three or four, covered with numerous slender spinules. Spores in the mass golden-yellow, globose, the surface reticulate, 10-12 mic. in diameter.

Growing on and inside of rotten wood. Plasmodiocarp an irregular patch, one to several centimeters in extent, the strands of the net about .5 mm. in thickness. A single reticulate plasmodium is usually converted without change of form into an individual plasmodiocarp.

II. CALONEMA, Morgan, gen. nov. Sporangia subglobose, irregular, sessile, without a hypothallus; the wall thin, marked with branching veins, irregularly dehiscent. Capillitium of slender tubules, arising from the base of the sporangium, repeatedly branched and with numerous free extremities; the surface traversed by a system of branching veins, ending in minute veinlets, which appear as irregular rings and spirals. Spores subglobose, yellow.

The habit of the single species is that of an Oligonema, and it has spores similar to those of most species of this genus, but the threads are long and branched, and they are fastened below to the base of the sporangium.

1. CALONEMA AUREUM, Morgan n. sp. Sporangia subglobose to turbinate, sessile, closely crowded and from mutual pressure quite irregular; the wall thin, marked with branching veins, golden-yellow in color, smooth and shining. Capillitium of threads more or less branched, 5-6 mic. in thickness, golden-yellow; the surface minutely venulose, and with larger rings and spirals, and sometimes with scattered spinules; the free extremities obtuse. Spores subglobose, yellow, the surface with elevated ridges combined into a network, 14-16 mic. in diameter. See Plate I, Fig. 21.

Growing on and within rotten wood. Sporangia quite irregular and variable in size, .3-.6 mm. in diameter. The beautiful venation of the wall of the sporangium is continued upon the surface of the threads of the capillitium.

III. TRICHIA, Haller. Sporangia regular and stipitate or sessile and somewhat irregular; the wall, at maturity, irregularly ruptured. The stipe more or less elongated or often wanting, usually resting on a hypothallus. Capillitium consisting of numerous short slender tubules, called elaters, intermingled with the spores and wholly free; elaters simple or rarely branched a time or two, each extremity terminating in a smooth tapering point; the spiral ridges parallel and conspicuous, 2-5 in number, smooth or spinulose. Spores globose, yellow, ochraceous, olivaceous.

The genus Trichia is unique among the Myxomycetes in having its capillitium composed of tubules, which are entirely free from the wall of the sporangium. The length of these free tubes varies usually between .3 mm. and .5 mm., being sometimes shorter, but seldom longer; they are typically cylindric, or equally thickened from end to end, or quite rarely they are thickened in the middle, and taper gradually to each extremity; the extremities terminate in a smooth tapering point, straight or sometimes a little curved or flexuous, which maintains an average length in each species. The spiral ridges wind around the thread almost invariably to the left, or with the hands of a watch; they are always more or less prominent and conspicuous, and usually maintain a regular curve and uniform interval between each other in the same species; their surface is either smooth, or sometimes it is invested with minute warts or spinules.

In all the species of this genus, however, irregular and abnormal elaters are occasionally met with among the typical ones. As these abnormal forms always arrest attention, and have been conceived to possess specific value, it may be well to note the principal of them.

1. The elater is sometimes branched. In two or three species the branching appears to be quite regular and not abnormal; still, even in these species, most of the elaters in the sporangia are not branched. In some cases the branching arises from confluence of two or more elaters.

2. Ellipsoidal swellings, or enlargements of the elater, sometimes occur, at one or both extremities, or at points intermediate between them; these always occur irregularly, and are essentially abnormal.

3. The smooth tapering point is rarely wanting, in which case the extremity presents a blunt end, the spiral ridges running to the end. More frequently the tapering points are multiplied, the elaters bearing two or three spines at the extremities; this often occurs in the species of Trichia, and also of Hemiarcyria with spinulose elaters.

4. The spiral ridges are sometimes defective, there being less than the typical number; sometimes they are merely displaced, there being a much wider interval between them than usual; rarely do they habitually wind about the thread in an irregular manner.

5. Under high magnifying power, fine ridges are sometimes seen running lengthwise of the elaters, bridging the intervals between the spirals. These were first observed by DeBary, in Trichia chrysosperma, but they have since been seen in the elaters of nearly every other species of Trichia, and also in species of Hemiarcyria.

The few species with elaters, so far as yet known, habitually irregular, defective and abnormal, are referred to the genus Oligonema.

The normal species of Trichia arrange themselves quite naturally into three sections.

Sec.1. A NACTIUM. Sporangia varying from globose to pyriform or turbinate, supported on a more or less elongated stipe. Spores globose, the surface minutely warted.

a. Elaters with very long tapering extremities.

1. TRICHIA FRAGILIS, Sow. Sporangia obovoid to pyriform or clavate, often fasciculate, stipitate; the wall a thin membrane, with a thick dense outer layer of brown-red granules. Stipes long, erect or curved, simple or usually fasciculate and often connate, arising from a thin hypothallus. Mass of spores and capillitium from reddish-brown to yellow and ochraceous; elaters simple, rarely branched, 4-5 mic. thick, with very long tapering extremities, ending in smooth points 8-12 mic. long; spirals, three or four, perfectly smooth. Spores globose, minutely warted, 10-12 mic. in diameter.

Growing on old wood. Sporangia with the stipe 2-4 mm. in height, the sporangium .6-.8 mm. in diameter, the stipe usually longer than the sporangium. The color quite variable, mostly dull red-brown or blackish-brown, more rarely yellow or coffee-brown, usually opaque, rarely shining.

2. TRICHIA FALLAX, Pers. Sporangium obovoid to pyriform or turbinate, rarely clavate, stipitate; the wall thin, smooth and shining, colored as the spores and capillitium. Stipe more or less elongated, simple, erect, brownish below, filled with roundish vesicles. Mass of capillitium and spores yellowish, ochraceous or olivaceous; elaters simple or sometimes with several branches, 4-6 mic. thick in the middle, tapering gradually to each extremity, ending in smooth tapering points, 20-40 mic. in length; spirals, three, perfectly smooth. Spores globose, minutely warted, 10-12 mic. in diameter. See Plate I, Fig. 22.

Growing on old wood. Sporangium with the stipe 2-4 mm. in height, sporangium .6-.8 mm. in diameter, the stipe usually longer than the sporangium. Under high magnifying power the spores are seen to be minutely reticulated.

b. Elaters cylindric, ending in a smooth tapering point.

3. TRICHIA SUBFUSCA, Rex. Sporangium globose, rarely globose-turbinate, stipitate; the wall thickish, dull tawny-brown above, shading to dark brown at the base. Stipe simple, erect, brown or blackish in color. Mass of capillitium and spores bright yellow; elaters simple, rarely branched, cylindric, 3.5-4 mic. in thickness, ending in smooth tapering points, 10-12 mic. in length; spirals, four in number, perfectly smooth. Spores globose, minutely warted, 11.5-12.5 mic. in diameter.

On old wood and bark, Adirondack Mountains, New York. Dr. George A. Rex. Sporangium .5-.8 mm. in diameter, the stipe equal in height to the diameter of the sporangium.

4. TRICHIA ERECTA, Rex. Sporangium globose to globose-turbinate, stipitate; the wall of both sporangium and stipe with a rough outer layer of brown scales and granules, which, on the upper surface of the sporangium, soon breaks up into irregular patches. Stipes long, erect, usually simple, rarely fasciculate and connate. Mass of capillitium and spores, bright yellow; elaters simple, cylindric, 4 mic. in thickness, ending in smooth points, 4-6 mic. long; spirals four, often united by intervening branches, covered with numerous irregular spinules. Spores globose, minutely warted, 12-14 mic. in diameter.

Growing on old wood and bark, Adirondack Mountains, New York, Dr. Geo. A. Rex. Sporangium .5-.8 mm. in diameter, the stipe about 1 mm. in height. This Trichia is conspicuous by the checkering or areolation of the upper surface in the mature sporangia, affording a sharp contrast between the brown patches and the yellow bands.

Sec.2. CHRYSOPHIDIA. Sporangia globose, obovoid or somewhat irregular, sessile, rarely with a short stipe, usually closely crowded. Spores globose, the surface minutely warted.

a. Elaters perfectly smooth.

5. TRICHIA VARIA, Pers. Sporangia globose, obovoid or somewhat irregular, gregarious and scattered or crowded, yellowish, ochraceous or olivaceous, sessile, or with a very short brown or blackish stipe. Mass of capillitium and spores yellow; elaters long, simple or sometimes branched a time or two, 4-5 mic. in thickness, ending in a smooth tapering point, 8-12 mic. long; spirals only two, smooth, very prominent in places, causing the elater to appear notched. Spores globose, oval or somewhat irregular, minutely warted, 10-14 mic. in diameter.

Growing in patches on old wood; a very common species. Sporangium .6-.8 mm. in diameter, or when irregular sometimes elongated to 1 mm. or more. Extremely variable as to the form of the sporangium, but readily recognized by its elaters.

6. TRICHIA ANDERSONI, Rex. Sporangia globose or obovoid, sessile, gregarious, closely crowded, or sometimes scattered, the wall thickened with minute scales, in color brownish-ochre or olivaceous. Mass of capillitium and spores yellow; elaters long, simple, 3-4 mic. in thickness, ending in a very long flexuous point, 14-18 mic. in length; spirals three or four, winding evenly and closely, perfectly smooth. Spores globose, minutely warted, 10-12 mic. in diameter.

Growing on the inside of bark of Acer. Sporangium .4-.5 mm. in diameter. The capillitium is deep orange and the spores olivaceous, but this difference in shade of color between spores and capillitium occurs in other species. Trichia advenula, Mass., is a closely related species, the swellings in the elaters having no specific value.

7. TRICHIA INCONSPICUA, Rost. Sporangia very small, subglobose, sessile, collected together in clusters, or scattered, without any hypothallus; the wall brown, smooth and shining. Mass of capillitium and spores yellow; elaters long, simple, cylindric, 3-4 mic. in thickness, ending in smooth tapering points, 6-7 mic. in length; spirals three or four, close, not prominent, perfectly smooth. Spores globose, minutely warted, 10-12 mic. in diameter.

Growing on bark of Platanus, etc. New York, Peck; Iowa, McBride. The sporangia spherical or reniform and very small.

b. Elaters spinulose.

8. TRICHIA IOWENSIS, McBride. Sporangia subglobose, sessile, gregarious, scattered, or sometimes close and confluent; the wall thickened with minute scales, reddish-brown in color. Mass of capillitium and spores yellow; elaters quite variable, usually very long, but sometimes very short, simple, rarely branched, the thickness unequal, 3-4 mic. in the same elater, with occasional thicker swellings, bearing numerous scattered spines, usually about as long as the thickness of the elater, but sometimes much longer, those at the ends being similar; spirals three or four, fine and close, in places nearly obsolete. Spores globose, or more or less irregular, minutely warted, 9-11 mic. in diameter.

Growing on old bark of Populus; Iowa, McBride. Sporangia .4-.5 mm. in diameter. This is a very curious species of Trichia; it suggests Ophiotheca Wrightii, but the elaters are short and simple, and there is no question as to the spirals upon them. I could find no branched elaters in my specimen.

9. TRICHIA SCABRA, Rost. Sporangia globose or somewhat irregular, sessile and closely crowded on a well-developed hypothallus; the wall thin, gold-yellow or orange to yellow-brown in color, smooth and shining. Mass of capillitium and spores orange or golden-yellow; elaters long, simple, 4-5 mic. in thickness, ending in a smooth tapering point, 5-8 mic. in length; spirals three or four, covered with numerous short acute spinules. Spores globose, minutely warted, 9-11 mic. in diameter. See Plate I, Fig. 23.

Growing on old wood in patches, sometimes several centimeters in extent. Sporangia .6-1 mm. in diameter. "The papillae, which cover the spore, show, when highly magnified, a distinct net-like pattern," McBride. The elaters of this species are subject to much irregularity in the way of abnormal swellings, duplicating the spines at the apex, etc.; the spinules are sometimes quite obsolete on some or all of the elaters of a sporangium.

Sec.3. GONIOSPORA, Fr. Sporangia obovoid to oblong, sessile and closely crowded on a well-developed common hypothallus. Spores with thick ridges upon the surface, which are combined into a more or less incomplete network of polygonal meshes.

The ridges of the epispore are 1-2 mic. in height, and do not present to the view more than two or three perfect polygons on a hemisphere of the spores; more often the reticulation is imperfect, the ridges being interrupted and defective. When highly magnified these ridges are seen to be "perforated through their thickness with one, two or three rows, or with clusters of cylindrical openings or pits, or are sculptured into intricate plexuses of minute reticulations with quadrilateral interspaces."

10. TRICHIA AFFINIS, DeB. Sporangia obovoid to oblong, sessile and closely crowded on a common hypothallus; the wall thin, golden-yellow to tawny or brownish-yellow, smooth and shining. Mass of capillitium and spores golden to tawny-yellow; elaters long, simple, 4-5 mic. in thickness, ending in a smooth tapering point, 6-10 mic. in length; spirals four, usually spinulose, rarely smooth. Spores angularly or irregularly globose, 10-12 mic. in diameter.

Growing on old wood and bark in small patches of a few millimeters to a centimeter or more in extent. Sporangia .6-.8 mm. in height by .4-.5 mm. in diameter. Trichia Jackii, Rost., is included in this species.

11. TRICHIA CHRYSOSPERMA, Bull. Sporangia oblong-obovoid to cylindric, sessile and closely crowded on a well-developed hypothallus; the wall thin, pale citron to olive-yellow, smooth and shining. Mass of capillitium and spores, golden to ochre-yellow; elaters long, simple, 6-8 mic. in thickness, ending in a smooth tapering point, 3-7 mic. in length; spirals four or five, usually smooth, rarely spinulose. Spores angularly or irregularly globose, 12-14 mic. in diameter.

Growing on old wood, in small patches, one to several centimeters in extent. Sporangia 1-2 mm. in height and .5-.6 mm. in diameter. This is readily distinguished from Trichia affinis by the larger and differently colored sporangia.

IV. OLIGONEMA, Rost. Sporangia subglobose, more or less irregular, sessile and closely crowded, often in heaps, one upon another, the wall thin, smooth and shining; hypothallus none. Capillitium scanty, composed of elaters habitually irregular and abnormal, intermingled with the spores; elaters simple or sometimes branched, commonly very short, but varying greatly in length, even in the same sporangium; the surface marked with faint spirals, with a few annular ridges, minutely punctulate or altogether smooth. Spores globose, yellow.

The species of this genus are to be regarded as degenerate Trichias. Of course, the abnormality is exhibited most markedly by the elaters; nevertheless, the sporangia of some of the species have a peculiar habit of heaping themselves upon each other.

A. Surface of the spores reticulate.

a. Elaters with projecting rings.

1. OLIGONEMA NITENS, Lib. Sporangia subglobose, irregular, sessile, closely crowded and heaped upon each other, the wall thin, yellow, smooth and shining. Mass of capillitium and spores yellow; elaters simple or sometimes branched, 3-4 mic. in thickness, with a few distant projecting rings, the surface smooth between, or with very faint spirals, the extremities obtuse, or sometimes with a minute apiculus. Spores angularly or irregularly globose, the surface reticulate, 11-14 mic. in diameter.

Growing in small patches on and within rotten wood. Sporangia .4-.5 mm. in diameter; the elaters variable, some with as many as a dozen projecting rings, some with but a few or nearly smooth. Trichia nitens, Libert.

2. OLIGONEMA PUSILLA, Schr. Sporangia subglobose, irregular, sessile, scattered or collected together in heaps; the wall thin, yellow, smooth and shining. Mass of capillitium and spores yellow; elaters simple or sometimes branched, 4 mic. in thickness, sometimes with thicker inflated portions, the surface marked with low faint spirals or perfectly smooth; the extremities rounded and usually terminating in a smooth point, 3-5 mic. in length—this point either curved, bent to one side or turned back, and twisted around the extremity as a ring. Spores angularly or irregularly globose, the surface reticulate, 11-14 mic. in diameter.

Growing in small clusters in rotten wood. Sporangia .3-.5 mm. in diameter; the elaters variable in length, scarcely exceeding 100 mic. and often much shorter. Trichia pusilla, Schroeter.

b. Elaters with no projecting rings.

3. OLIGONEMA FLAVIDUM, Peck. Sporangia obovoid to oblong, sessile, closely crowded and irregular from mutual pressure; the wall thin, yellow, shining, punctulate or minutely granulose. Mass of spores and capillitium yellow; elaters simple or sometimes branched, 3-4 mic. in thickness, sometimes with thicker inflated portions; the surface punctulate or minutely warted, occasionally marked with very faint spirals; the extremities usually rounded and obtuse, sometimes acute, and rarely with a minute apiculus. Spores angularly or irregularly globose, the surface reticulate, 11-14 mic. in diameter. See Plate I, Fig. 24.

Growing in dense patches on old wood and mosses. Sporangia .4-.6 mm. in diameter, and reaching 1 mm. in height, the elaters usually rather long, sometimes quite long and branched.

4. OLIGONEMA BREVIFILA, Peck. Sporangia subglobose, irregular, sessile, crowded, forming clusters or effused patches; the wall thin, yellow, densely granulose and venulose. Mass of capillitium and spores ochre-yellow; elaters simple or sometimes branched, often very short and fusiform, when elongated having long tapering extremities, sometimes with irregular swollen portions; the surface minutely granulose and rugulose, here and there a few spinules, occasionally with indistinct spirals. Spores angularly or irregularly globose, the surface reticulate, 11-12 mic. in diameter.

Growing on old wood and mosses. Sporangia .4-.5 mic. in diameter, the elaters varying greatly in length, some not more than 20 or 30 mic. long, others more than 100 mic. in length.

B. Spores minutely warted.

5. OLIGONEMA FULVUM, Morgan n. sp. Sporangia rather large, subglobose, sessile, closely crowded and more or less irregular; the wall tawny yellow, very thin and fragile, smooth, shining and iridescent. Mass of capillitium and spores tawny yellow; elaters simple or sometimes branched, mostly very short, 4 mic. in thickness, sometimes with thicker swollen portions; the surface marked with low smooth spirals, in places faint and obsolete; the extremities rounded and obtuse, usually with a very minute apiculus, 1-3 mic. in length. Spores globose, minutely warted, 10-13 mic. in diameter.

Growing on an old effused Sphaeria. Sporangia .6-.8 mm. in diameter, the elaters mostly 40-80 mic. in length, rarely much longer and sometimes shorter; the longer elaters and those that are branched often arise from confluence of the shorter ones.

EXPLANATION OF PLATE I.

Fig. 13.—Perichaena depressa, Lib.

Fig. 14.—Ophiotheca Wrightii, B. & C.

Fig. 15.—Lachnobolus globosus, Schw.

Fig. 16.—Arcyria Cookei, Massee.

Fig. 17.—Arcyria minor, Schw.

Fig. 18.—Heterotrichia Gabriellae, Massee. (After Massee.)

Fig. 19.—Hemiarcyria plumosa, Morgan.

Fig. 20.—Hemiarcyria funalis, Morgan.

Fig. 21.—Calonema aureum, Morgan.

Fig. 22.—Trichia fallax, Pers.

Fig. 23.—Trichia scabra, Rost.

Fig. 24.—Oligonema flavidum, Peck.

NOTE.—Each figure exhibits the sporangium as it appears magnified about 100 diameters, and the capillitium and spores magnified about 500 diameters.



* * * * *

THE MYXOMYCETES OF THE MIAMI VALLEY, OHIO.

BY A. P. MORGAN.

Third Paper.

(Read February 6, 1894.)



ORDER VI. STEMONITACEAE.

Sporangia globose or ovoid to oblong and cylindrical, stipitate; the wall very thin and fragile, soon disappearing. Stipe tapering upward and continued within the sporangium as a more or less elongated columella. Capillitium of slender brown threads, arising from numerous points of the columella, repeatedly branching and usually anastomosing to form a network, persistent and rigidly preserving the outline of the sporangium. Spores globose, brown or violaceous.

This order is readily distinguished by the brown persistent capillitium, arising from a lengthened columella, and rigidly maintaining the form of the sporangium.

Table of Genera of Stemonitaceae.

A. Stipe and columella brown or black.

a. The columella scarcely reaching the center of the sporangium.

1. CLASTODERMA. Threads of the capillitium forking several times, but not combined into a network.

2. LAMPRODERMA. Threads of the capillitium branching and anastomosing to form a network.

b. The columella extending beyond the center of the sporangium.

3. COMATRICHA. Threads of the capillitium forming only an interior network, attaining the wall by numerous more or less elongated free extremities.

4. STEMONITIS. Threads of the capillitium forming an interior network of large meshes and a superficial network of smaller meshes.

5. ENERTHENEMA. Threads of the capillitium pendent from a discoid membrane at the apex of the columella.

B. Stipe and columella white or yellowish.

6. DIACHAEA. Threads of the capillitium branching and anastomosing to form a network.

I. CLASTODERMA, Blytt. Sporangium regular, globose, stipitate; the wall very thin and fragile. Stipe elongated, tapering upward, entering the sporangium as a very short or nearly obsolete columella. Capillitium arising by a few branches from the apex of the columella, these branches forking several times at a sharp angle, but not combined into a network, the ultimate branchlets long and free, or only connected together at their tips by persistent fragments of the sporangial wall. Spores globose, violaceous.

The claim of this genus to be distinguished from Lamproderma must rest upon the fact that the branchlets of the capillitium do not anastomose and form a network. It is the same as the genus Orthotricha of Wingate.

1. CLASTODERMA DE BARYANUM, Blytt. Sporangium very small, globose; the wall early disappearing, except the minute fragments which persist at the extremities of the capillitium, and a narrow collar at the base of the columella. Stipe very long, thick and brown below, tapering upward to a pellucid oblong swelling, thence abruptly narrowed to the apex; the columella extremely short, capillitium of very slender pale-brown semi-pellucid threads, divergently forking, the ultimate branchlets often joined 2-4 together at their tips by fragments of the sporangial wall. Spores globose, even, violaceous, 8-9 mic. in diameter. See Plate XI, Fig. 25.

Growing in rather a scattered way on old rotten wood. Sporangium .20-.25 mm. in diameter, the stipe .7-1.3 mm. long. Orthotricha microcephala, Wingate. Blytt's species was found in Norway, Wingate's in Pennsylvania; I have met with it several times in this locality. It is possibly more common than it appears, as by reason of the difficulty of seeing the minute sporangium it is passed by as some mold. Blytt's spore measurements are 9.5-11 mic.; in some specimens I have seen a few spores of this size, but they are abnormal.

II. LAMPRODERMA, Rost. Sporangia regular, globose, stipitate; the wall thin and fragile, rugulose, shining with metallic tints, breaking up irregularly and gradually falling away. Stipe more or less elongated, smooth, brown or black in color, arising from a hypothallus, tapering upward and entering the sporangium as a short columella scarcely reaching the center. Capillitium of numerous threads radiating from the columella, usually forking several times and combined into a net by lateral anastomosing branchlets. Spores globose, brown or violaceous.

Lamproderma is distinguished by the shining metallic tints of the sporangial wall, and by the short columella scarcely reaching half the height of the sporangium.

1. LAMPRODERMA PHYSAROIDES, A. & S. Sporangium globose; the wall with a silvery metallic luster, at length breaking up and falling away. Stipe long, slender, brown or blackish, arising from a small circular hypothallus; columella clavate, obtuse, not reaching the center of the sporangium. Capillitium of brownish-violet threads, arising from the upper part of the columella; these branch repeatedly at a sharp angle, form an intricate network of elongated meshes, terminating at the wall in numerous short free branchlets. Spores globose, minutely warted, bright brown, 12-14 mic. in diameter.

Growing on old wood, moss, etc., New York, Chas. H. Peck. Distinguished by the pale silvery sporangial wall and the clear brown spores.

2. LAMPRODERMA ARCYRIONEMA, Rost. Sporangium small, globose; the wall dark bronze, with a silvery sheen when loosened from the spores, soon breaking into scales and falling away. Stipe long and slender, smooth, shining and black, rising from a thin hypothallus; the columella short cylindric, variable in length, but not attaining the center of the sporangium. Capillitium arising by division of the apex of the columella into several primary branches; these immediately separate into numerous slender flexuous brown threads, which unite and form a dense network of small arcuate meshes, the ultimate branchlets not free. Spores globose, even, violaceous, 6-7 mic. in diameter. See plate XI, Fig. 26.

Growing on old wood of Juglans and Carya. Sporangium .3-.5 mm. in diameter, the stipe three or four times as long. The columella is somewhat variable, it sometimes forks or divides immediately on entering the sporangium, at other times it is longer and cylindric, with more slender primary branches. The meshes of the capillitium resemble those of Arcyria, whence the name. This is the Stemonitis physaroides, A. & S. var. suboeneus of Lea's Catalogue.

3. LAMPRODERMA VIOLACEUM, Fr. Sporangium depressed-globose, convex above and more or less flattened and umbilicate beneath; the wall shining with steel or violet, blue and purple tints, deciduous. Stipe short, stout, brown or blackish in color, arising from a thin, brown, common hypothallus; columella cylindric, or tapering slightly to an obtuse apex, attaining the center of the sporangium. Capillitium of numerous slender threads, radiating from the upper part of the columella; these threads are brown below, with a variable outer portion colorless; they branch a few times and form an interior network of elongated meshes, outwardly arching and freely anastomosing they give rise to an external network of small irregular meshes, they then attain the wall by innumerable short, simple, or forked free branchlets. Spores globose, minutely spinulose, violaceous, 9-11 mic. in diameter. See plate XI, Fig 27.

Growing on old wood, mosses, etc., late in Autumn. Sporangium .5-.8 mm. in diameter, the stipe about the same length. The capillitium is sometimes most of it colorless and flaccid; sometimes it is all brown and rigid except the minute free extremities.

4. LAMPRODERMA ARCYRIOIDES, Somm. Sporangium globose or ellipsoid, and somewhat elongated; the wall with tints of violet, purple, and blue, deciduous. Stipe usually short, or sometimes nearly obsolete, brown or blackish in color, arising from a strongly-developed hypothallus; the columella cylindric or slightly tapering upward, and obtuse, reaching nearly to the center of the sporangium. Capillitium of numerous pale-brown threads, radiating from the apex of the columella; these fork directly from the base, are bent and flexuous, and are combined into a dense, intricate net, with abundant free extremities. Spores globose, spinulose, violaceous, 13-16 mic. in diameter.

Growing on old leaves, wood, etc. Sporangium .5-.8 mm. in diameter, the stipe variable in length from very short to 1 mm. long or beyond. Lamproderma columbinum, Pers. is a doubtful species, the forms of that name being easily distributed between the present species and L. physaroides.

5. LAMPRODERMA SCINTILLANS, B. & Br. Sporangium globose; the wall shining with colors of blue, purple, and bronze, deciduous. Stipe long, slender, smooth, and shining, brown or blackish, rising from a thin, brown, common hypothallus; columella cylindric or slightly tapering to the obtuse apex, not reaching the center of the sporangium. Capillitium of numerous brown threads, originating about the apex of the columella; these fork several times, with few anastomosing branchlets, and terminate at the wall in long, free extremities. Spores globose, minutely warted, violaceous, 7-9 mic. in diameter. See Plate XI, Fig. 28.

Growing on old leaves, moss, etc., in early Spring. Sporangium .3-.5 mm. in diameter, the stipe from once to twice as long. This is Lamproderma irideum of Massee's Monograph. I am indebted to Arthur Lister, Esq., of London, for the identification of my specimens with Stemonitis scintillans, B. & Br., and with Lamproderma irideum, Cke.

III. COMATRICHA, Preuss. Sporangia various in shape, from globose or ovoid to oblong and cylindric, stipitate; the wall very thin and fugacious. Stipe more or less elongated, smooth and black, arising from a common hypothallus, tapering upward, entering the sporangium and prolonged nearly or quite to the apex as a columella. Capillitium arising from numerous points of the columella throughout its entire length; the threads immediately branching and anastomosing to form an interior network, attaining the wall by numerous more or less elongated free extremities. Spores globose, brown or violaceous.

This genus is not sharply limited from Stemonitis. The species with very short free ends, and consequently with superficial meshes approximate to the wall, are near the form of Stemonitis. But it may be observed that in these species, the meshes of the capillitium become smaller gradually outward, the sides of the superficial meshes are arched away from the wall, and they are in contact with it only by the free extremities.

Sec.1. TYPHOIDES. Threads of the capillitium repeatedly branching and anastomosing, to form a dense network of small meshes, with innumerable short, free extremities.

1. COMATRICHA TYPHINA, Roth. Sporangia short, erect or a little curved, cylindric or usually narrowing slightly upward, the base quite blunt, the apex more rounded, growing together on a thin hypothallus. Stipe and columella brown or blackish, tapering upward and vanishing near the apex of the sporangium, the stipe much shorter than the columella. Capillitium of slender flexuous tawny-brown threads; these branch repeatedly, forming an intricate network of small irregular meshes, ending in very short free extremities. Spores globose, violaceous, very minutely warted, 6-8 mic. in diameter.

Growing on old wood, mosses, etc. Sporangium with the stipe 2-4 mm. in height, the stipe much the shorter, the sporangium .35-.40 mm. in thickness. Stemonitis typhoides, Fries, S. M.

2. COMATRICHA AEQUALIS, Pk. Sporangia usually more or less inclined or curved and nodding, cylindric, obtuse at each end, growing together on a thin hypothallus. Stipe and columella slender, smooth, black, extending nearly or quite to the apex of the sporangium, the stipe longer than the columella. Capillitium of very slender flexuous tawny-brown threads; these branch repeatedly, forming an intricate network of small irregular meshes, ending in very short free extremities. Spores globose, minutely warted, dark violaceous, 7-9 mic. in diameter.

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