B. Sporangia sessile.

22. Physarum plumbeum Fr. Sporangia small, globose or obovoid, sessile, on a narrow base, gregarious, sometimes close but seldom confluent; the wall a thin violaceous membrane, with a very thin layer of small white scales and minute granules of lime, sometimes naked. Capillitium a loose net-work of slender tubules, with slight expansions at the angles; the nodules of lime white, numerous, more or less elongated, irregularly lobed and branched. Spores globose, even, violaceous, 7–9 mic. in diameter.

Growing on old leaves, sticks, etc. Sporangia .3-.4 mm. in diameter, quite regular in shape, attached by a narrow base, sometimes by a mere point, rarely confluent. The lime on the wall of the sporangium is rather scanty, sometimes altogether absent, and the nodules of lime in the capillitium are rather small. The species is figured by Micheli N. P. G. Tab. 96, Fig. 9. It is named by Fries S. M., III, p. 142. It is figured again by De Bary, Die Mycetozoen, Tafel I.

23. Physarum atrum Schw. Sporangia sessile, subglobose or oblong, by confluence, more or less elongated, bent or flexuous and branched; the wall a thin violaceous membrane, rugulose, covered by a wrinkled and reticulate layer of white granules of lime, which sometimes become thin or disappear. Capillitium a loose net-work of tubules, more or less expanded at the angles; the nodules of lime white, numerous, large, irregularly lobed and branched. Spores globose, very minutely warted, violaceous, 8–10 mic. in diameter.

Growing on old leaves, bark, grasses, etc.; apparently the most common of these three cinereous species. Sporangia .3-.5 mm. in thickness, some of them roundish or oblong, others elongated to several millimeters. The sporangium is often elegantly reticulate as observed by Schweinitz even when the lime is quite scanty. In Saccardo's Sylloge Berlese changed the name to Physarum reticulatum, but this is unnecessary, as the Physarum atrum of Fries is not a Myxomyces.

24. Physarum cinereum Batsch. Sporangia large, subglobose, sessile, gregarious, sometimes close and confluent; the wall a thin violaceous membrane, with a closely adherent layer of minute granules, over which are scattered irregular white scales of lime. Capillitium of tubules forming a loose net-work, with wide expansions at the angles; the nodules of lime numerous, white, very large, with pointed angles and lobes, by confluence often branched and reticulate, and occasionally forming a pseudo-columella in the center of the sporangium. Spores globose, minutely warted, dark violaceous, 10–13 mic. in diameter.

Growing on old wood, leaves, etc. The sporangia .4-.6 mm. in diameter, more or less irregular. The great abundance of lime in the capillitium and the large distinctly warted spores distinguish this species. Physarum cinereum of Persoon's Synopsis, Didymium cinereum of Fries' Systema. The only American specimens I have of this species are from Iowa (McBride) and from Nebraska (Webber).

25. Physarum virescens Ditm. Sporangia large, subglobose, irregular and unequal, sessile, gregarious, sometimes crowded, but not often confluent; the wall a thin membrane, violaceous, or in places yellowish, with a dense layer of yellow or greenish-yellow scales and granules of lime. Capillitium a loose net-work of tubules, with wide expansions at the angles; the nodules of lime large, numerous, yellow or greenish-yellow, more or less elongated, lobed, and branched. Spores globose or somewhat irregular, very minutely warted, violaceous, 9–11 mic. in diameter.

Growing on old leaves, mosses, etc. Sporangia .5-.8 mm. in diameter, occasionally by confluence more elongated. Though found in all parts of the country, the species seems rare. This is not the Physarum virescens described by Rostafinski.

26. Physarum rubiginosum Fr. Sporangia subglobose, sessile, gregarious; the wall a thin hyaline membrane, thickly covered with large irregular scales of lime, orange to red or dark red in color, breaking up irregularly. Capillitium of hyaline tubules, forming a loose irregular net-work, more or less expanded at the angles; the nodules of lime large, angular, and irregular, sometimes confluent, orange to dark red in color. Spores globose, very minutely warted, dark violaceous, 9–11 mic. in diameter.

Growing on old wood, leaves, mosses, etc. Sporangia .6-.8 mm. in diameter. Physarum fulvum Fries S. M., III, p. 143. A rare species. It should not be confounded with Physarum lateritium.

27. Physarum serpula Morgan, n. nom. Plasmodiocarp roundish or oblong to much elongated, bent, annular and flexuous, sometimes by confluence branched and reticulate; the wall a firm yellowish membrane, with a thin, rough, closely adherent coat of granules of lime, dull ochre to lemon-yellow and orange in color. Capillitium a dense net-work of tubules, for the most part filled with lime, only here and there short, slender, empty spaces; the nodules large, numerous, white or yellow, angular and with pointed lobes and branchlets. Spores globose, minutely warted, dark violaceous, 9–11 mic. in diameter. See Plate XV. Fig. 65.

Growing on leaves, bark, lichens, etc. Plasmodiocarp .3-.4 mm. in thickness and of varying length. This species is in the herbarium of Schweinitz, at Philadelphia, with the name Physarum reticulatum; it is described by George Massee as Physarum gyrosum; by Lister it is incorporated with several other species under Badhamia decipiens.

28. Physarum contextum Pers. Sporangia sessile and closely crowded together, roundish or more or less elongated, flexuous and complicate, the apex plane or impressed; the wall a firm yellowish membrane, covered by a thick pulveraceous layer of lime, white, ochraceous or yellow, easily crumbling and breaking up. Capillitium a loose net-work of tubules, much expanded at the angles; the nodules of lime very large, white or yellow, numerous, angular, and irregular, by confluence lobed and branched, sometimes massed together in the center of the sporangium. Spores globose, minutely warted, dark violaceous, 10–13 mic. in diameter.

Growing on bark, leaves, mosses, etc. Sporangia with a width of .3-.5 mm. and varying in length from .5 mm. to 1 or 2 mm. The sporangia are often so much crowded as to appear to be grown together. Diderma ochroleucum B. & C. belongs to this species. Physarum conglomeratum Fr. is a closely related species, with smaller and smoother spores. I have not met with this.

29. Physarum diderma Rost. Sporangia large, irregularly globose or oblong, sessile, but without a hypothallus, closely crowded together and sometimes confluent. The wall composed of two distinct and separate layers; the outer a thick, uneven, crustaceous, snow-white layer of lime; the inner a thin, violaceous membrane, cinereous from the adherent granules of lime, or free from them, and iridescent. Capillitium of tubules forming a loose net-work, with wide expansions at the angles; the nodules of lime numerous, snow-white, large, irregular, with pointed angles and lobes, sometimes confluent in the center of the sporangium. Spores globose, minutely warted, dark violaceous, 9–10 mic. in diameter.

Growing on wood, bark, and mosses. Sporangia .8–1.0 mm. in diameter, more or less irregular. The wall of the sporangium is exactly like that of certain species of Diderma. This species must be rare, as I have met with it but twice in ten years, and I am not aware that it has ever been found by any one else.

VIII. FULIGO Haller. Aethalium a compound plasmodiocarp; the component sporangia branching and anastomosing in every direction, complicate and grown together; the walls of the sporangia a thin membrane, coated with minute, roundish granules of lime. Capillitium of tubules forming a net-work of irregular meshes, more or less expanded at the angles, the tubules containing in greater or less abundance irregular nodules of lime. Spores globose or sometimes ellipsoidal, violaceous.

The genus is readily distinguished from Spumaria by the round granules of lime upon the walls of the sporangia.

§1. Aethalium Link. Aethalia large; the lime in the capillitium scanty, the nodules small, ellipsoidal, or fusiform.

a. Aethalium with a thick fragile common cortex.

1. Fuligo rufa Pers. Plasmodium a large soft mass with a peculiar odor and golden yellow in color. Aethalium very large, pulvinate, orbicular, elongated, or quite irregular, extremely friable, the surface tawny or ferruginous to ochraceous and whitish. The long narrow, sinuous sporangia closely compacted, entirely grown together and inseparable, covered by a thick common cortex, and seated on a much thickened hypothallus; walls of the sporangia a thin pellucid membrane, coated by a thin layer of white granules of lime. Capillitium of very slender tubules, extending across from wall to wall, sparingly branched and scarcely forming a network, not at all or only slightly expanded at the angles; the tubules for the most part empty, here and there with slight fusiform or elongated swellings containing granules of lime, occasionally bearing roundish or ellipsoidal nodules of larger size. Spores globose, nearly smooth, violaceous, 6–9 mic. in diameter.

Growing on old trunks in woods in great abundance from early Spring to Winter. Aethalium 3–6 or sometimes many centimeters in extent and 1–2 cm. in thickness. The common cortex and the hypothallus are a millimeter or more in thickness; they are composed of successive layers of thin plates of membrane coated with granules of lime.

b. Aethalium naked, i. e., without a common cortex.

2. Fuligo violacea Pers. Plasmodium a soft effused mass, dark red or wine-colored. Aethalium large, pulvinate or effused, orbicular or more or less elongated and irregular, the surface minutely pitted and perforate, furnished with a scanty layer of lime, whitish or yellowish to brick-red in color, leaving naked purple and violet spots and patches, seated on a thin membranaceous brick-red hypothallus. Sporangia long, narrow, and sinuous, closely packed together; the walls a thin violaceous membrane, rugulose and iridescent, with scattered granules, or nearly destitute of lime. Capillitium of slender violet tubules, forming a loose net-work, with slight expansions at the angles; the tubules with numerous rather large vesicular expansions, ellipsoid or fusiform in shape, and scantily furnished with lime. Spores globose, nearly smooth, pale vinous, 6–8 mic. in diameter.

Growing on old trunks in woods; not uncommon in this region. Aethalium 1–3 or more centimeters in extent, and 5–10 mm. in thickness. The vesicles of the capillitium vary from 15–30 or sometimes to 50 mic. in diameter, their inner surface is usually coated by a single layer of granules of lime, they are rarely filled with lime and sometimes are naked entirely; when dry many of them are to be found collapsed. See Plate XV. Fig. 66.

3. Fuligo flava Pers. Plasmodium effused lemon-yellow. Aethalium mostly effused, irregular, the surface reticulate, pitted and perforate, entirely naked, pale yellow to lemon-yellow and greenish-yellow, the hypothallus thin or scarcely evident. Sporangia laterally much compressed, flexuous, and gyrose, not everywhere grown together, but forming a dense reticulum; the walls a thin, pellucid membrane, with a dense layer of lemon-yellow granules of lime. Capillitium of short and very slender tubules, sparingly branched and scarcely forming a net-work, not expanded at the angles; the tubules very scantily furnished with lime, in scattered, small, fusiform nodules, white or lemon-yellow. Spores globose, very minutely warted, violaceous, 7–9 mic. in diameter.

Growing on mosses, old leaves, sticks, etc.; not common. Aethalia in irregular patches 2–4 cm. or more in extent, sometimes almost reduced to a simple plasmodiocarp. This species furnishes a clear notion of the structure of the aethalium in the other species, on account of the sporangia being but loosely compacted and not entirely grown together. The Fuligo vaporaria Pers., of the green-houses and gardens I have never seen; the Mucor septicus Linn., was thought to be the plasmodium of this. Linnæus's description is simply "Mucor unctuosus flavus." See Plate XV. Fig. 67.

§2. Aethaliopsis Zopf. Aethalium small; lime abundant in the capillitium, the nodules numerous and large, angular and irregular.

4. Fuligo muscorum A. & S. Plasmodium effused, golden yellow. Aethalium small, subpulvinate, irregular, the surface furnished with scattered, irregular scales of lime, whitish or ochraceous to golden yellow in color, arising from a thin, white, membranaceous hypothallus. Sporangia closely packed and grown together; the walls a thin, violaceous membrane, rugulose, with a thin, closely adherent layer of granules of lime. Capillitium a loose net-work of tubules, widely expanded at the angles; the tubules for the most part filled with lime, the nodules white or yellowish, numerous, very large, angular and irregular, sometimes confluent with pointed lobes and branchlets. Spores irregularly globose, minutely warted, dark violaceous, 9–11 mic. in diameter.

Growing on leaves, twigs, mosses, etc. Aethalium from 2 or 3 mm. to a centimeter or more in extent. I have a specimen of Fuligo simulans Karsten, from Karsten himself; it is identical with my specimens of Fuligo ochracea Peck. There could be no better representation of these specimens made at that time than the description and figure of Fuligo muscorum A. & S., in the Conspectus.

5. Fuligo cinerea Schw. Plasmodium milk-white, changing to cinereous. Aethalium effused, variable in extent, the surface rugulose and perforate, white, the hypothallus thin or scarcely evident. Sporangia variously contracted and grown together, forming a dense reticulum; the walls a thin pellucid membrane, with a thick white outer layer of granules of lime. Capillitium a loose net-work of tubules, widely expanded at the angles, the tubules for the most part filled, with lime, the nodules white, numerous, very large, angular, and irregular, lobed and branched. Spores globose or oval, minutely warted, dark violaceous, 10–15 × 10–12 mic.

Growing on old leaves, herbaceous stems, etc. I find it most abundantly about the horse barn, upon the old straw and manure, sometimes running out onto the green herbage. Aethalium from a few millimeters to several centimeters in extent. Upon the testimony of Dr. Geo. A. Rex this is both Enteridium cinereum and Lachnobolus cinereus of Schweinitz's North American Fungi as represented in his herbarium. It is Physarum ellipsosporum of Rostafinski. It is no doubt also Aethaliopsis stercoriformis Zopf. See Plate XV. Fig. 68.

IX. BADHAMIA Berk. Sporangia large, subglobose or obovoid, sometimes depressed, substipitate or sessile; the wall a thin membrane, with an outer layer of minute roundish granules of lime, irregularly dehiscent. Stipe poorly developed, sometimes a mere strip of the hypothallus, often wanting. Capillitium of thick tubules, attached on all sides to the wall of the sporangium, combined into a net-work of large meshes, more or less expanded at the angles; the tubules containing minute roundish granules of lime throughout their whole extent. Spores large, subglobose, dark violaceous.

The peculiar character of this genus is that the granules of lime are distributed along the whole interior of the tubules of the capillitium; this makes the net-work rigid, and on this account a firmer support for the wall of the sporangium.

1. Badhamia capsulifera Bull. Sporangia subglobose or obovoid, sessile, on a thin pallid or yellowish hypothallus, which sometimes sends out narrow bands or strings of membrane of variable length, bearing sporangia singly or in clusters. Wall of the sporangium a thin pellucid membrane, mostly even or somewhat rugulose and iridescent, coated by a very thin layer of white granules of lime. Capillitium of rather slender tubules, forming an open net-work of very large meshes, only slightly expanded at the angles; the tubules coated within by a very thin layer of white granules of lime. Spores subglobose or obovoid, adhering together in clusters of six to twenty or more, distinctly warted on the outer exposed surface, dark violaceous, 10–13 mic. in diameter.

Growing on old bark, leaves, etc. Sporangia .8–1.4 mm. in diameter. Badhamia hyalina and B. capsulifera of Rostafinski's monograph are here included together; he distinguished the former by the "sporangia in clusters always exactly globose," a distinction first made by Chevallier; otherwise the characters are the same in both.

2. Badhamia utricularis Bull. Sporangia subglobose or obovoid, sessile, on a thin pallid or yellowish hypothallus, which often separates into narrow strips and strings of membrane of variable length, bearing the sporangia singly or in clusters. Wall of the sporangium a thin violaceous membrane, rugulose and iridescent, shining with purple, blue, and violet tints, with a thin layer of white granules of lime. Capillitium of thick tubules, forming an open net-work of large meshes, more or less expanded at the angles, the tubules coated within by a thin layer of granules of lime. Spores subglobose, minutely warted, dark violaceous, 10–13 mic. in diameter.

Growing on old wood, bark, herbaceous stems, etc. Sporangia .5–1.0 mm. in diameter, usually growing in clusters, sometimes suspended by the strings of membrane. Rostafinski's distinction between this and the preceding species in regard to the spores holds good so far as my specimens are concerned. Badhamia magna Peck, I have never seen. George Massee includes all four of these species in one composite species, which he names Badhamia varia.

3. Badhamia papaveracea B. & Rav. Sporangia subglobose or obovoid, substipitate or sessile, growing close together; the wall a thin violaceous membrane, rugulose and iridescent, with a very thin coat of white granules of lime. Stipe very short, brown or blackish, sometimes reduced to merely a thickened blackish base to the sporangium. Capillitium of thick tubules, forming an open net-work of large meshes, more or less expanded at the angles; the tubules with an inner lining of very minute white granules of lime. Spores adhering together in clusters of six to twenty, each spore subobovoid, the free portion more distinctly warted, 10–12 mic. in diameter.

Growing on old wood, bark, etc. Sporangia .6–1.0 mm. in diameter. Readily distinguished by its black base or black stipe and the elegant clusters of its spores, which stick together most persistently. See Plate XV. Fig. 69.

4. Badhamia orbiculata Rex. Sporangia much depressed, orbicular or somewhat irregular, umbilicate often both above and below, gregarious, sometimes growing close together and confluent, stipitate or sessile. The wall a thin pellucid membrane, with a thin layer of minute granules of lime, which are sometimes raised into small scales and fine ridges. Stipe very short, black, sometimes reduced to merely a blackish base to the sporangium. Capillitium of thick tubules, forming a scanty irregular net-work, with wide expansions at the angles; the tubules filled with white granules of lime. Spores subglobose, very minutely warted, dark violaceous, 12–15 mic. in diameter.

Growing on old bark, herbaceous stems, etc. Sporangia .4-.8 mm. in diameter, sometimes by confluence larger. This species seems near Badhamia verna Smfdt, but the latter everywhere is described as sessile, while in the former the short black stipe is nearly always distinguishable.

5. Badhamia affinis Rost. Sporangium hemispherical, or much depressed, the base flattened or umbilicate, stipitate, erect or often cernuous; the wall a thin pellucid membrane, coated with minute white granules of lime, which are frequently raised into scales and ridges. Stipe short, erect or bent at the apex, black, expanding at the base into a small hypothallus. Capillitium of thick tubules, forming an open net-work of large meshes, more or less expanded at the angles; the tubules filled with white granules of lime. Spores subglobose, minutely warted, dark violaceous, 14–18 mic. in diameter.

Growing on mosses and upon the bark of maple trunks. Sporangium .6–1.0 mm. in diameter, the stipe about the same length. Rostafinski's description is based upon a specimen found in Chili, South America, by Bertero; it is recorded in this country by Peck. I find it in some seasons quite abundant. The spores are very large, in some specimens averaging 17 mic. See Plate XV. Fig. 70.

6. Badhamia decipiens Curtis. Sporangia gregarious, sessile, globose, oval or oblong, by confluence sometimes more elongated; the wall a somewhat thickened and firm yellow or yellow-brown membrane, covered with large, thick scales of lime, tawny to golden yellow or orange in color. Capillitium of thick tubules, forming an open network, more or less expanded at the angles; the tubules filled throughout with yellow granules of lime. Spores globose, very minutely warted, lilac, 10–12 mic. in diameter. See Plate XV. Fig. 71.

Growing on old wood and bark. Sporangia .6–1.0 mm. in length by .6-.7 mm. in thickness. My specimens were determined by Dr. George A. Rex by comparison with a specimen from Curtis in the herbarium of the Philadelphia Academy of Sciences. This species should not be confused with what we have described as Physarum serpula. Physarum chrysotrichum B. & C., is no doubt the same thing. Badhamia nitens Berk., which is also golden yellow, has not yet been found in this country; it will readily be distinguished from the present species by its clustered spores.

7. Badhamia panicea Fr. Sporangia sessile, subglobose or oblong, more or less irregular, gregarious; the wall a thin, pellucid membrane, covered with large, irregular, very thick, white scales of lime. Capillitium of thick tubules, forming a loose net-work of rather small meshes, with wide expansions at the angles; the tubules filled with white granules of lime, sometimes confluent toward the base of the sporangium. Spores subglobose, very minutely warted, dark violaceous, 11–14 mic. in diameter.

Growing on old wood, bark, leaves, etc. Sporangia .8–1.6 mm. in length, with a thickness of .7–1.0 mm. This species appears to be rare; the only specimens known to me in this country I have from Professor Thos. A. Williams, of South Dakota; they are identical with European specimens received from Lister. Physarum paniceum Fries, S. M., III, p. 141; it approaches Physarum cinereum Batsch.

8. Badhamia lilacina Fr. Sporangia globose or obovoid, sessile or rarely substipitate, closely crowded together on a thin, brownish hypothallus; the wall a firm, hyaline membrane, with a thick, smooth, continuous outer-layer of lime, varying in color from gray-white or drab to lilac and flesh color. Capillitium of very thick tubules, forming a dense net-work of small meshes; the tubules stuffed with granules of lime, which are white or colored somewhat as those in the wall, often confluent in the center of the sporangium. Spores globose, minutely warted, dark violaceous, 11–14 mic. in diameter.

Growing on wood, leaves, mosses, etc. Sporangium .5-.7 mm. in diameter. The outer crustaceous layer of lime on the wall crumbles and falls away, as in some species of Diderma. The white form is Diderma concinnum B. & C.; the lilac or flesh-colored form is Physarum lilacinum of Fries, S. M., p. 141. I have seen it colored only white and drab. Under a high magnifying power the sculpturing of the spores is seen to be peculiar.

X. SCYPHIUM Rost. Sporangium obovoid to oblong-obovoid, stipitate or subsessile; the wall a thickened, brownish membrane, the surface entirely naked or only the upper portion covered with granules of lime, breaking up irregularly about the apex. Stipe variable in length, arising from a common hypothallus and prolonged within the sporangium as a columella. Capillitium of thick tubules, proceeding from numerous points of the columella and forming a dense network; the tubules filled with lime throughout their whole extent. Spores large, subglobose, dark reddish-brown.

This genus differs from Badhamia by the columella which gives origin to the capillitium. The sporangia in the species composing it, resemble those of Craterium, and to this genus they are referred by Massee, but the capillitium is that of Badhamia.

1. Scyphium rubiginosum Chev. Sporangia gregarious, obovoid, stipitate; the wall a thickened reddish-brown membrane, the upper part covered by a thin layer of white granules of lime, the lower basal portion naked, strongly venulose and more persistent. Stipe long, erect, reddish-brown, expanding at the base into a brown hypothallus, prolonged within the sporangium to more than half its height as a columella. Capillitium of thick tubules, forming a dense net-work of small meshes; the tubules stuffed with white granules of lime. Spores irregularly globose, minutely warted, dark reddish-brown, 12–15 mic. in diameter.

Growing on old wood, mosses, etc. Sporangia .6-.8 mm. in height by .5-.6 mm. in diameter, the stipe from once to twice the height of the sporangium. This is Physarum rubiginosum Chevallier, Flor de Paris. It is also Craterium obovatum Peck. See Plate XV. Fig. 72.

2. Scyphium curtisii Berk. Sporangia oblong-obovoid, stipitate or subsessile, usually growing in clusters; the wall a thick, firm, reddish-brown membrane, venulose and reticulate, nearly destitute of lime. Stipes variable, commonly very short, sometimes confluent, arising from a brown hypothallus, prolonged within the sporangium to about half its height. Capillitium of thick tubules, forming a dense network of small meshes; the tubules stuffed with white granules of lime. Spores irregularly globose, minutely warted, dark reddish-brown, 12–15 mic. in diameter.

Growing on old wood, leaves, grass, etc. Sporangium .4-.7 mm. in height by .3-.4 mm. in diameter, the stipe often reduced to a mere point or cushion on the hypothallus, and varying thence to nearly the length of the sporangium. The sporangium is narrower than in the preceding species, and the brown wall is usually without granules of lime. It is Didymium curtisii Berk. Rostafinski and Massee both preserve it distinct from S. rubiginosum. See Plate XV. Fig. 73.

EXPLANATION OF PLATE XV.

Transcriber's Notes

The Table of Contents and List of Illustrations was added; not part of the original papers.

Page 4 & Vol. XV, Plate III: 'Lycogola' changed to 'Lycogala'.

Page 18: 'exigum' changed to 'exiguum'.

Page 24: 'stiptiate' changed to 'stipitate'.

Page 27: 'fasiculate' changed to 'fasciculate'.

Page 35: 'A nactium' Unknown word. Unchanged.

Vol. XVI, Plate I: 'Cookii' changed to 'Cookei'.

Page 48: 'Stermonitis scintillans' changed to 'Stemonitis scintillans'.

Page 84, 85(2): 'circumcissile' changed to 'circumscissile'.

'Network' and 'net-work' are used interchangeably throughout.

Use of accents is inconsistent, especially in illustrations.

Links to Plates XIII, XIV and XV added in html version.

Plates moved closer to referencing text.