Chapter XII: Section 2: =Tilmadoche= Fries (5)

Aethalium pulvinate, 2-8 cm. broad, at first silvery white, later less lustrous, the cortex irregularly and slowly deciduous; hypothallus at first conspicuous as a white margin extending round the entire aethalium, evanescent without, but persisting as a firm membrane beneath the spore-mass, pseudo-capillitium abundant, tending to form erect central masses which persist long after the greater part of the fruit has been scattered by the winds; spore-mass umber, spores by transmitted light pale, reticulate over about two-thirds of the surface, the remainder slightly warted, 8-9 mu.

Not common. Often confused with the following, the spores of the two forms being very much alike; the internal structure, entirely different, and once compared, the two are thereafter easily distinguished at sight by external characters. The sporangial make-up is indifferent, confused. It represents a phase in development whence might issue columellae with capillitium-branches or distinct tubular sporangia with persisting walls; or are such structures here but reminiscent only? Compare _Amaurochaete atra_, where similar conditions prevail. There differentiation goes on to the formation of a structure of which _Stemonitis_ is type; here the sporangium-wall becomes dominant; suffers modification for spore-disposal, an idea reaching fair expression in _Cribraria_ and _Dictydium_.

The plasmodium is white, noted Bulliard. Fries cites with approval the words of Schweinitz,--"color corticis ab initio argenteus sericeo nitore insignis; sed deinde sordescit e griseo in subfuscum vergens." Sometimes the surface does indeed shine as silver!

The fructification appears to be isolated in each case; the entire plasmodium consumed in a single plasmodiocarp.

Widely distributed. Maine to California, and south.

=2. Enteridium= _Ehrenberg_

1818. _Enteridium_ Ehrenberg, Link and Spreng., _Jahrb., Bd._ II.,
p. 55.

Fructification aethalioid; the confluent sporangia inextricably interwoven, the walls perforate by large openings, the resultant network of broad plates and bands widening at the points of intersection.

The genus _Enteridium_ is distinguished from _Reticularia_ chiefly by the more perfectly developed sporangial walls. These are everywhere membranous and do not show the abundant filiform dissipation so characteristic of _Reticularia_. The resultant structure in _Reticularia_ is a mass of more or less lengthened and anastomosing threads; in _Enteridium_, an exceedingly delicate but sufficiently persistent sponge. The "net-like, three-winged skeleton" referred to by Rostafinski results from the union at one point of three adjoining sporangia. Compare the section of the adjoining cells of a honeycomb.

Of this genus there are but two or three species, all so far occurring in our territory.

=Key to the Species of Enteridium=

_A._ Fructification umber brown 1. _E. splendens_

_B._ Fructification olivaceous 2. _E. olivaceum_

_C._ Fructification minute, 1-2 mm. 3. _E. minutum_

1. ENTERIDIUM SPLENDENS _Morg._

PLATE I., Figs. 1, 1 _a_, 1 _b_; PLATE XII., Figs. 4, 5.

1876. _Reticularia_ (?) _rozeanum_ Rost., _Mon. App._, p. 33.
1889. _Enteridium rozeanum_ (Rost.) Wing., _Proc. Phil. Acad._,
p. 156.
1892. _Enteridium rozeanum_ Wingate, Macbr., _Bull. Lab. Nat. Hist.
Iowa_, II., p. 117.
1893. _Reticularia splendens_ Morg., _Jour. Cin. Soc._, p. 11.
1899. _Enteridium splendens_ Morg., Morg. _in litt._

Aethalium pulvinate, even, or somewhat irregular, unevenly swollen or inflated, lobate or compound, covered by an exceedingly thin, generally smooth, shining, but never white, pellicle or cortex, brown, from 1-6 cm. in diameter; hypothallus white, often wide extending; capillitium none; the sporangial walls thin and brown forming a network as above described; spore-mass umber, spores by transmitted light pale, about two-thirds of the surface reticulate, the rest nearly smooth, 7-9 mu.

Very common, especially west, on decaying logs and stumps of every description. Easily distinguished by its brown color and smooth, shining, though uneven surface. The plasmodium as it emerges to form fruit is pale pink or flesh color, slowly deepening to brown as maturity advances. The first emergence is a watery white.

New England, Canada, to Minnesota and Nebraska, South Dakota.

In 1876 Rostafinski provisionally referred to the genus _Reticularia_ certain specimens received from M. Roze of Paris. Thirteen years later in correspondence with M. Roze, Mr. Wingate satisfied himself that the specimens discovered by Roze were the same as our common enteridium. He therefore, _l. c._, applied to our American forms the name they have widely borne, _E. rozeanum_. Mr. Lister, _Jour. of Botany_, Sept. '91, applied the Rostafinskian name to certain English specimens. Thereafter to be known as _Reticularia lobata_ Rost. and so fixed the status of that species. From all the literature before us it appears that Mr. Lister was right. _R. lobata_ List. (now _Liceopsis lobata_ List.) Torr., occurs in various parts of Europe, while our American species of _Enteridium_ is yet to be discovered on that side of the sea!

Were the latter native to the old world at all, it had surely been seen long ago. It is large and fine, and could not have escaped the famous collectors of the last two hundred years. Although it has been sent by students from this side of the ocean to Europe for more than thirty years, it has not even adventitiously appeared.

It therefore appears that our American species is known to Europe through Mr. Wingate's reference only.

Twenty years ago in correspondence with Mr. Wingate it was learned that the material received by him from M. Roze was but a small fragment, crushed flat, and even this was at that time no longer in evidence. This specimen was itself _not part of the gathering submitted to Rostafinski_; but only the fragment of something _appearing in 1890 in the same locality_!

... "something not the same,
But only like its forecast in men's dreams."

When we further reflect that the spores of species of several of the forms now in review, _Tubifera_, _Reticularia_, _Enteridium_, are not without difficulty distinguished, it is easy to see that Mr. Wingate's specific reference has narrow foundations to say the least. It seems now likely that Father Torrend's _Liceopsis_, _Reticulara lobata_ R., M. Roze's aftermath, and all, are but the depauperate forms of some tubifera!

_E. rozeanum Wing._, is therefore the synonym for an ill-defined something in Western Europe and need not further here concern us as far material reference goes.

In any case, what induced Mr. Wingate to pull Rostafinski's uncertain description of a problematic form across the sea, to attach it to our clearly defined and well known American species, changing the Polish description the while to make it fit, is hard to understand; especially in view of the fact, by Wingate admitted, that Rex had in his letters to Morgan already named the American type _Enteridium umbrinum_. The two students differed as to generic reference, and later on Morgan published _Reticularia splendens_ Morg.; rather than _R. umbrina_ (Rex) Morg. because he was using _R. umbrina_ Fr. for what is generally known as _R. lycoperdon_ (_Bull._)

It would then appear that when Wingate sought to impose the Rostafinskian specific name upon our American form by changing (fixing!) Rostafinski's generic reference, and by re-writing the specific description from the pages of the _Monograph_ in order to claim identity, he was entirely without justification, especially since he knew the species appropriately named by his colleague, Dr. Rex, and had the name as used in the Rex and Morgan correspondence.

In brief; Mr. Wingate proceeded to re-describe Rostafinski's rozean specimen and referred a long-known American form (very different) to the European specimen as type. Wingate's description is right; he had the American material before him; but his cited type is worthless, an entirely different thing.

Does the reader care to see what the European _type_ of our common form, Wingate _teste_, really looks like, let him consult the _Jour. of Botany_, Vol. XXIX., p. 263, 1891.

2. ENTERIDIUM OLIVACEUM _Ehr._

1818. _Enteridium olivaceum_ Ehr.

Aethalium depressed flat, oval or elongate, .3 cm. in extent, .6 mm. thick when fresh, glossy, smooth, greenish-olivaceous-brown; within a spongy net-work representing sporangial walls which are thin, pale olivaceous, perforate by circular openings, meshes surrounded by wide plates; spores in clusters, six or more together, ovoid, distinctly warted at the wider end, pale olivaceous, 9-11 mu.

This, the type of the genus, is a very distinct species of this by its structure readily distinguished form. Fries thought the species might represent a less perfectly-developed reticularia, and therefore wrote _Reticularia olivacea_ noting, however, the clustered spores and the lack of hypothallus.

Common, as would appear, in Europe and in S. America; rare with us. Reported from N. Hampshire and we have one specimen from Colorado.

3. ENTERIDIUM MINUTUM _Sturg._

1917. _Enteridium minutum_ Sturg., _Mycologia_, IX, p. 328.

Aethalia rounded or elongate, pulvinate, pale umber in color, seated on a broad membranous base, 1.5-2 mm. in diameter; wall wrinkled and usually marked with small scattered pits, pale-yellow, membranous; walls of component sporangia, membranous, minutely roughened, perforated with round openings, the margins of which show many free threads; or reduced to irregular, anastomosing strands arising from the base of the aethalium, with membranous or net-like expansions at the angles and with many delicate, free, pointed ends. Spores pale-yellow, usually united in twos or threes, and ovoid or flattened on one side; when free, globose, very minutely spinulose, 9.5-10.5.

Colorado: _Dr. Sturgis._

=3. Dictydiaethalium= _Rostafinski_

1873. _Dictydiaethalium_ Rost., _Versuch_, p. 5.
1875. _Clathroptychium_ Rost., _Mon._, p. 224.

Aethalium depressed, flat; the sporangia erect, regular, prismatic by mutual pressure, the peridia convex above, wanting at the sides and within the aethalium represented by vertical threads marking the angles and passing from base to summit.

This genus is readily recognized by the internal structure of the aethalium. The lateral wall-openings, which, as we have seen, characterize the sporangia of the preceding genus, here become extreme, occupying to such extent the lateral wall-space of each sporangium that only threads remain to mark the vertical angles.

In 1873 Rostafinski applied the generic name here adopted, because he thought he discovered close relationships with _Dictydium_. In 1875, believing his first impressions erroneous, and desirous that the nomenclature might not at once mislead the student and perpetuate the memory of his own mistake, the same author proposed the name by which the genus has generally ever since been known--_Clathroptychium_. However sensible the latter conclusion reached by our Polish author, it is plainly contrary to all rules of priority.

Our region shows but a single widely distributed species,--

1. DICTYDIAETHALIUM PLUMBEUM (_Schum._) _Rost._

PLATE I., Figs. 2, 2 _a_, 2 _b_.

1803. _Fuligo plumbea_ Schum., _Enum. Saell._, No. 1410.
1833. _Licea rugulosa_ Wall., _Cr. Fl. Ger._, IV., p. 345.
1873. _Dictydiaethalium plumbeum_ (Schum.) Rost., _Versuch_, p. 5.
1875. _Clathroptychium rugulosum_ (Wallr.) Rost., _Mon._, p. 225.
1894. _Dictydiaethalium plumbeum_ Rost., List., _Mycetozoa_, p. 157.

Aethalium thin, very flat, olivaceous or ochraceous, smooth, under the lens punctate, in section showing the columnar or prismatic sporangia, which are normally six-sided, having at the edges six simple threads, the remains of peridium, extending from base to apex, where the peridium remains intact, arcuate; hypothallus prominent, radiating far around the aethalium, silvery white; spores in mass, ochraceous, or dull brownish yellow, by transmitted light almost colorless, rough 9-10 mu.

Not rare, on decaying logs, especially of _Tilla americana_, where in the same place successive fructifications follow each other sometimes for weeks together in the latter part of summer and early fall. The aethalium is generally elliptical or elongate, 2-3 cm. in extent, sometimes irregular or branched, varying in color according to degree of maturity, weathering, etc. Plasmodium at first watery, then pink, or flesh-colored.

Eastern United States; common. Toronto;--_Miss Currie._

_E._ CRIBRARIACEAE

Sporangia distinct, more or less closely gregarious, stipitate, the peridium opening, especially above, by a well-defined network formed from thickenings in the original sporangial wall.

=Key to the Genera of the Cribrariaceae=

_A._ Peridial thickenings in form of an apical net
with definite thickenings at the intersections
of the component threads 1. CRIBRARIA

_B._ Peridial thickenings in form of parallel
meridional ribs connected by delicate
transverse threads 2. DICTYDIUM

=Cribraria= (_Pers_) _Schrader._

1794. _Cribraria_ Persoon, Roemer, _N. Bot. Mag._, I., p. 91, in part.
1797. _Cribraria_ Schrader, _Nov. Gen. Plant._, p. 1, in part.
1875. _Cribraria_ Rostafinski, _Mon._, p. 229.

Sporangia distinct, gregarious or closely crowded, globose or obovoid, stipitate; the stipe of very varying length; the peridium simple, marked within by distinct and peculiar, granular, thickenings, which below take the form of radiating ribs, supporting the persisting cup, _calyculus_, and above, by extremely delicate anastomosing branches, unite to weave a more or less regular net with open polygonal meshes; spores various, more often yellowish or ochraceous, sometimes brown, reddish, or purple.

The genus _Cribraria_, as limited by Persoon, included all forms in which the peridium is thin, evanescent half-way down, or entirely, and in which capillitium, as Persoon regarded the case, is formed of a network of reticulate threads surrounding the spores. Schrader redefined the genus; opposed Persoon's view as to the capillitial nature of the net, and separated the genus _Dictydium_, but by imperfect limitations,--in fact, chiefly because of the more completely evanescent peridium. Fries follows Schrader. Rostafinski first clearly separated the two genera, and his classification is here adopted. Nevertheless, after reviewing the subject entire one is more and more inclined to appreciate the commendation of Fries; "Auctor Schrader, qui insuper plurimas species detexit, et hoc et sequens genus ita proposuit ut sequentes vix aliquid addere valuerint."

As to the habitat of the cribrarias, the remark of Schrader is still pertinent--"in vetustissimis plenariae destructionis proximis arborum truncis"--for all the species. Rotten, coniferous wood seems to be preferred, but the decayed logs of trees of other orders are by no means refused. Rotten oak forms a very common habitat.

=Key to the Species of Cribraria=

_A._ Sporangia with spores ochraceous or brownish.

_a._ Sporangia larger, .5 mm. or more.

1. Net poorly developed, sometimes merely
indicated 1. _C. argillacea_

2. Net conspicuous, nodes expanded, not swollen.

i. Calyculus reticulately thickened,
ill-defined above 2. _C. macrocarpa_

ii. Calyculus with radiant lines or ribs;
net small-meshed; free ends none 6. _C. aurantiaca_

iii. Net wide-meshed, calyx rufous 4. _C. rufa_

iv. Calyx replaced by ribs 5. _C. splendens_

3. Net conspicuous, nodules swollen.

i. Net-threads simple; free ends many 7. _C. dictydioides_

ii. Net-threads often parallel in twos
or threes 8. _C. intricata_

_b._ Sporangia small, less than .5 mm.

1. Nodes not expanded 3. _C. minutissima_

2. Nodes well shown.

i. Calyculus distinctly marked by
radiant lines, nodes round 10. _C. tenella_

ii. Calyculus minute or none;
nodes prominent 11. _C. microcarpa_

_B._ Sporangia more or less marked with purple or violet tints.

_a._ Purple or violet throughout.

1. Net poorly developed 12. _C. violacea_

2. Net well developed.

i. Meshes regular and the nodes
distinct 14. _C. elegans_

ii. Meshes and nodules irregular 13. _C. purpurea_

_b._ Purple tints confined chiefly to plasmodic
granules on the calyculus and stipe.

Net with nodes well expanded.

i. Stipe short, not more than double the
sporangium; net and calyculus both
well developed 9. _C. piriformis_

ii. Stipe many times the sporangium,
weak 15. _C. languescens_

iii. Stipe slender, sporangium
copper-colored 16. _C. cuprea_

1. CRIBRARIA ARGILLACEA _Pers._

PLATE XII., Figs. 12, 13; PLATE XVII., Fig. 1.

1791. _Stemonitis argillacea_ (Pers.) Gmel., _Syst. Nat._, II., 1469.
1796. _Cribraria argillacea_ Pers., _Obs. Myc._, I., p. 90.

Sporangia dull ochraceous-olivaceous, globose, nearly 1 mm. in diameter, sessile or short stipitate, closely gregarious or crowded, the peridial walls at maturity smooth, shining, except above, long persistent, obscurely reticulate, with irregular thickenings which at the apex at length present the appearance of an irregular, coarsely meshed net without nodal thickenings; stipe very short, stout, erect, reddish brown, spore-mass ochraceous, spores by transmitted light pale, spinulose, 5-6 mu.

This species stands just on the border-line between the tubiferas and the genus now before us. While on the one hand it possesses many characters such as the habit, form of sporangium, which are distinctly tubuline, on the other it shows in the upper peridial wall definite reticulations which suggest _Cribraria_. In freshly formed sporangia the reticulations are barely visible in the crown; later on they are more manifest, until, as spore-dispersal proceeds; the cribraria characters come out with sufficient distinctness, and in empty sporangia the reticulations may be seen to affect the entire peridial wall. The nodes are not expanded. The spores are pale by transmitted light, spinulose, about 6 mu. Plasmodium lead-colored. Found sometimes in large patches on rotten logs of various species. Not uncommon. Cf. _Lindbladia effusa_.

New England, New York, Pennsylvania, South Carolina, Ohio, Illinois, Iowa, Washington; Canada.

2. CRIBRARIA MACROCARPA _Schrader._

PLATE XVII., Fig. 2.

1797. _Cribraria macrocarpa_ Schrad., _Nov. Gen. Plant._, p. 8.

Sporangia more or less closely gregarious, yellowish brown, pear-shaped or obovate, large, .8-1 mm. in diameter, stipitate; stipe brown furrowed, erect or often nodding, about equal to the sporangium or longer; calyculus distinct, marked by numerous dark brown radiating ribs, iridescent, perforate above, deeply dentate, and merging gradually into the elegant network, of which the dark nodes are more distinctly expanded about half way up, less so at the apex and below, the filaments exceedingly delicate, simple, with occasional free ends projecting into the small meshes; spore-mass yellowish, spores by transmitted light almost colorless, minutely roughened, 5-6 mu.

Perhaps the most striking characteristic of the present species, aside from its large size, is the peculiarly perforated cup or calyculus. Schrader's artist failed him here completely. The structure is exceedingly delicate, the peridium between the ribs and reticulations reduced to the last degree of tenuity, with the iridescence of the soap-bubble, here and there lapsed entirely. Withal the structure seems firm enough and persists until all the spores are dissipated by the wind.

Easily distinguished from the preceding, its only rival in size, by the obovate or turbinate, netted sporangium, its much longer stem, and flat, perfectly formed nodes.

Rare. New York, North Carolina, South Carolina, Oregon; Toronto, Canada.

3. CRIBRARIA MINUTISSIMA _Schweinitz._

PLATE XVII., Figs. 6, 6 _a_.

1832. _Cribraria minutissima_ Schw., _N. A. F._, No. 2362.

Sporangia scattered, orange or nut-brown, very minute, .1-.3 mm. or less, globose or ellipsoidal, stipitate, erect or nodding; hypothallus none; stipe short, 1-3 times the sporangium, filiform, tapering upward, brown; the calyculus variable, sometimes well marked and separated from the net when fully mature, by a shallow constriction, more commonly small or entirely wanting, especially in the spherical sporangia; net simple, large meshed, without nodal expansions, the threads flattened; spore-mass yellow, spores by transmitted light, pale, nearly smooth, 5-6 mu.

A most beautiful tiny species. Generally in all the specimens before us, a perfect, spherical net, firm enough to retain its place and structure after all the spores have been scattered. When mature the spore-mass seems to roll about as a ball, freely within the net, the spores being thus gradually dispersed. The calyculus when present is without veins. _C. minima_ Berk. & C., and _C. microscopica_ Berk. & C. are doubtless the same thing. _Grev._, II., p. 67, 1823. See also _Bot. Gaz._, XIX., 397.

Rare. Pennsylvania, South Carolina, Missouri, Iowa; Black Hills, South Dakota.

4. CRIBRARIA RUFA (_Roth_) _Rost._

PLATE XIX., Fig. 8.

1788. _Stemonitis rufa_ Roth, _Fl. Germ._, I., p. 548.
1794. _Cribraria rufescens_ Pers., Roemer, _N. Mag. Bot._, I.,
p. 91.
1797. _Cribraria fulva_ Schrad., _Nov. Gen. Pl._, p. 5.

Sporangia scattered, sub-globose or turbinate, dark or reddish orange, .5-.7 mm. in diameter, erect, stipitate; stipe about equalling the height of the sporangium or longer, dark brown or black; calyculus one-third to one-half the sporangium, the margin toothed, the wall ribbed and continuous with the open wide-meshed net; the network deep yellow or orange, the threads flattened; the nodes not thickened, little differentiated; spores concolorous, by transmitted light, pale yellow, verruculose, 5-7 mu.

Similar to the preceding, but generally much larger and not so much inclined to brown. The size, however, is extremely variable in sporangia from the same plasmodium (reported white), some no larger than those of the species reckoned most minute.

Oregon. _Professor Morton Peck._

5. CRIBRARIA SPLENDENS (_Schrader_) _Rost._

PLATE XIX., Fig. 10.

1797. _Dictydium splendens_ Schrad., _Nov. Gen._, p. 14.
1801. _Cribraria splendens_ (Schrad.) Pers., _Syn. Fung._, p. 191.

Sporangia gregarious, globose, dusky yellow when filled with spores, dull or dusky brown when these are discharged, stipitate; stipe long, 3-4 times the sporangium, subulate, erect-nodding, brown; hypothallus none; network brown, with large meshes, imperfectly defined nodes and flattened threads; calyculus none, its place supplied by nine or ten distinct, firm ribs which radiate from the stipe and support the net, branching to blend with its reticulations; spore-mass yellow, spores by transmitted light, colorless, smooth or nearly so, 6-7.5 mu.

Of this species two specimens only are before us, one from Muscatine County, Iowa, and one from Washington (state). The species seems thus to have wide range, but to be exceedingly rare. It differs from all other American forms, so far described, in the peculiar development of the calyculus. Rostafinski emphasizes the persistence of the peridial wall and the peculiar gleaming of the metallic tints, displayed by all the structures. These particulars we have not been able to verify. Such characters may be incident to age or conditions of development. At all events, in forms which in all other respects seem to agree exactly with Rostafinski's descriptions, the colors are dull and without any noticeable iridescence. The spores in our specimens are also a little larger than quoted. Rostafinski gives 5-6 mu; Massee, 5-7 mu.

6. CRIBRARIA AURANTIACA _Schrader._

PLATE XVII., Fig. 3, and XIX., Fig. 7.

1797. _Cribraria aurantiaca_ Schrad., _Nov. Gen. Pl._, p. 5.

Sporangia gregarious, spherical, dusky or yellowish stipitate, nodding; the calyculus variable, generally prominent, more or less distinctly marked by fine, delicate radiating venules, the margin denticulate, the teeth numerous and slender, supporting the well-defined globose net; network made up of very tenuous threads, forming rather small irregular brownish nodules and showing only here and there a free extremity; stipe generally short, two or three times the diameter of the sporangium, sometimes longer, tapering upward, brown, slender, arcuate above; spore-mass yellow or ochraceous, spores by transmitted light, colorless, 5-6 mu, almost smooth.

This widely distributed and very variable species is generally recognized by the large sporangia, .5-.9 mm., comparatively short stipe, simple net, and more or less orange color. The color is an uncertain thing even in the sporangia, which rise from one plasmodium. Schrader, however, made this feature so far diagnostic that he placed the more pronouncedly yellow forms in the species _C. aurantiaca_ and set off as _C. vulgaris_ forms in which more dusky tints prevail. The dark-colored forms have also usually longer stipes, but so much is dependent upon the climatic conditions prevalent at the time of fruiting, that this feature also is indeterminate. Rostafinski's figures, 21 and 26, Tab. II., show the characteristic nodules and the typical net structure. It is to be observed that Fig. 21 represents higher magnification; otherwise the two figures are very much alike.

New England, New York, Pennsylvania, Maryland and South, Ohio, Washington, California; Canada, Toronto.

7. CRIBRARIA DICTYDIOIDES _Cke. & Balf._

PLATE I., Figs. 5, 5 _a_, 5 _b_, and XIX., 6, 6 _a_, 6 _b_.

1881. _Cribraria dictydioides_ Cke. & Balf., _Rav. Fung. Am._, 475.

Sporangia gregarious, of medium size, globose, cernuous, stipitate; the stipe long, slender, tapering upwards, dull brown in color; hypothallus none; the calyculus variable, sometimes well developed, as in _C. aurantiaca_, sometimes rudimentary or represented only by irregular, node-like ribs; the network delicate, the meshes small, few-sided; the nodules large, prominent, brown, irregular, with several radiating, free, projecting threads, beside the single continuous filaments which pass from node to node; spore-mass pale, ochraceous; spores nearly smooth, colorless, 5-7 mu.

This seems to be the most common _Cribraria_ in the Mississippi valley. It is generally distinguished by the scant calyculus and the beautiful richness of its clear delicate net. The stellate nodules especially above, emit filamental rays in all directions, but are, notwithstanding, united by single, unpaired threads only. The calyculus is often entirely absent, and this has been supposed the typical condition; but, on the contrary, there often may present itself a cup as distinct as in _C. aurantiaca_. See, for this variation, _Bot. Gaz._ XIX., p. 398. The rather large sporangia, .6-.7 mm., the nodes joined by single threads, the remaining radiant threads, many or few, but very short--these seem to be the most distinctly diagnostic characters, and these are sufficiently constant to separate this species easily from _C. intricata_ on the one hand and _C. tenella_ on the other. Mr. Lister considers this merely a form of the next species.

Abundant on rotten logs of every sort, especially oak; common on the lower side of rotting pine planks in wooden walks along the streets everywhere. N. A. F., 2095, seems to belong here.

Pennsylvania, Ohio, North Carolina, Missouri, Illinois, Iowa, Nebraska.

8. CRIBRARIA INTRICATA (_Schrad._) _Rost._

1797. _Cribraria intricata_ Schrad., _Nov. Gen. Pl._, p. 7.

Sporangia gregarious, globose, large, .7-1 mm. in diameter, nut-brown or olivaceous, erect, stipitate; stipe long, slender, purplish brown, flexuous; calyculus variable, sometimes occupying one-third of the sphere, when it is delicately costate, concolorous with the stipe, and passes over to the net by a distinctly toothed or serrulate margin, sometimes represented by irregular ribs or costae only; net well differentiated, the threads delicate, transparent, yellow, connecting large black nodules, running from one to the other in pairs or sometimes three together, free ends not numerous, the meshes few-sided, often triangular; spores in mass, dull olivaceous, under the lens pallid, nearly smooth, 6-7 mu.

A very rare species, if indeed it occur in this country. At least the form figured by Rostafinski, Tab. II., Fig. 27, and Massee, Pl. 1, Fig. 11, has not come to our notice. The parallelism of the net threads is a touch added by Rostafinski; Schrader does not mention it. Lister makes this species include the preceding. The form described in _Bull. Lab. Nat. Hist. Ia._ II., p. 119, is _C. dictydioides_.

Reported from New York, New England and Pennsylvania.

In the English _Monograph_ we are repeatedly assured that this species is common in the United States. The statement is made possible only by the inclusion of the form originally described from America and truly abundant east of the Rocky Mountains, _C. dictydioides_ Cke. & Balf.; _C. intricata_, by all accounts, just as preeminently the species of Europe. It is true that Schrader did not emphasize the parallel connecting threads by which later authorities distinguish the form; he had little occasion so to do, even did his figures intend accuracy in each detail, which they did not, and Rostafinski's, though his drawing is a diagram, certainly knew what he was doing. Cooke, in his list for Great Britain, quotes the Polish text without dissent, and Massee follows and illustrates; so that there can be no doubt as to what the European species is.

In any cribraria the presence or relative obsolesence, of the calyculus is of little taxonomic import since that structure is variable in every species. In the latest edition of Mr. Lister's work, the American form is entered as a variety in "hot-houses"; apparently adventitious; it is indeed related to the European form but is a geographic species.

9. CRIBRARIA PIRIFORMIS _Schrader._

PLATE XVII., Fig. 9; PLATE XIX., Fig. 9.

1797. _Cribraria piriformis_ Schrad., _Nov. Gen. Pl._, p. 4.

Sporangia gregarious, small, .3-.5 mm., turbinate or globose, erect, purplish brown, stipitate; stipe comparatively short, tapering upward, longitudinally furrowed, purple or brown; calyculus very well defined, about one-third the sporangium, not ribbed, flattened or even umbilicate below, the margin plainly denticulate, dusky brown; the net simple, the meshes large, triangular, with few free ends; the nodules small, globose or undifferentiated, slightly convex or flat; spore mass dull, yellowish brown; spores by transmitted light pale ochraceous or salmon-tinted, nearly smooth, 5-6 mu.

Schrader defined this beautiful form chiefly by its shape. This, though variable, is yet generally so far pyriform as to show distinct contraction toward the stipe. The well-defined calyculus is narrowed below and eroded or denticulate above. The cyanic tints due to the presence on the calyculus of radiating lines of purplish granules about one-half the size of the spores, the net open, uniform, the stipe rather stout, short, and distinctly furrowed, rising often from a small hypothallus--these are marks of this species. The net suggests _C. tenella_, but the latter species is much smaller, has a different stem, much longer and unfurrowed. The cup here is more nearly that of some form of _C. intricata_, but is better defined, passing into the net very abruptly by the simple intervention of projecting teeth.

Apparently rare. Our specimens are from New York, through the courtesy of Dr. Rex, Virginia, North Carolina, Iowa, Oregon, Colorado, and represent, as usual a modification of the European type, _C. notabilis_ Rex. Miss Lister, _Mon., 2nd ed._, writes var. _notabilis_.

Colorado forms are remarkable for dense brown coloration.

10. CRIBRARIA TENELLA _Schrader._

PLATE XVII., Fig. 5.

1797. _Cribraria tenella_ Schrad., _Nov. Gen. Pl._, p. 6.

Sporangia gregarious, small, .3-.5 mm. in diameter or smaller, olivaceous or ochraceous, long-stipitate, nodding; stipe slender, dark brown or blackish, very long, reaching 6 mm., weak and flexuous; calyculus variable, sometimes well defined, brown, costate, sometimes represented by the costae only connected by a thin, transparent membrane; net well differentiated, the meshes small, irregular, the nodes small, black, more or less globular, prominent, connected by transparent threads with occasional or a few free ends; spores in mass, olivaceous-ochraceous, under the lens pallid, globose, smooth, 5-7 mu.

Very common eastward and south, on the weathered surface of rotten wood. Generally easily recognized by its very long stipe, small, globose sporangium dotted with numerous small roundish nodules projecting plainly above the general surface. The obconic calyculus is always represented in the outline if not in definite structure.

New England, New York, Pennsylvania, Ohio, Tennessee, Illinois, Missouri, Iowa, Canada; Toronto,--_Miss Currie._

11. CRIBRARIA MICROCARPA (_Schrad._) _Persoon._

PLATE XVII., Fig. 4.

1797. _Dictydium microcarpum_ Schrad., _Nov. Gen. Pl._, p. 13.
1801. _Cribraria microcarpa_ Schrad., Pers., _Syn._, p. 190.
1875. _Cribraria microcarpa_ (Schrad.) Rost., _Mon._, p. 235.
1892. _Cribraria microcarpa_ Schrad., Massee, _Mon._, p. 63.
1893. _Cribraria microcarpa_ Schrad., Morg., _Myx. Mi. Vall._, p. 15.
1899. _Cribraria microcarpa_ Schrad., Macbr., _N. A. S._, p. 168.
1911. _Cribraria microcarpa_ Pers., Lister, _Mycetozoa, 2nd ed._,
p. 183 (?).

Sporangia loosely gregarious, very small, .2-.3 mm. in diameter, yellow ochraceous, stipitate, nodding; stipe comparatively stout, dark brown or blackish, tapering upward, often twisted at the apex as in _D. cancellatum_; calyculus none, represented by simple ribs which give off at intervals free or floating branchlets before blending into the common net; net well developed, the meshes large, the nodes small, irregular, though often rounded and prominent, black, connected by delicate transparent threads, with free ends few or none; spore-mass yellow, fading to ochraceous; spores pale, smooth, globose, 6-7 mu.

This species resembles at first sight the preceding, and has been often mistaken for it. As a matter of fact, the distinctions are generally very sharp. In the first place, the sporangia, when carefully measured, are seen to be not more than half as great in diameter; the meshes of the net, on the other hand, are much wider, the whole structure more compact. The nodules are like those of _tenella_, but are much fewer. The stipe is shorter, the cup wanting, and the costae are few and simple. The color suggests _C. aurantiaca_. The habitat and distribution as _C. tenella_.

To anyone who will read the account of the species as given by the English _Mon., 2nd ed._, p. 183, it is immediately apparent that the author has in mind a different form from that seen and described in our territory and previously noted by the authors of Europe. These from Schrader down, agree in portraying a brunescent form with yellow spores; Mr. Lister enters it with the cyanic series and so describes and figures it throughout. Schrader figures a nut-brown species; Rostafinski uses that descriptive term in connection with the general appearance when fresh, but gives the spore-mass yellow; only in the stipe does he find another tint, nut-brown-purple. The figure, 145 in the _Monograph_ now before us portrays, except in color, our _C. tenella_ exactly. Dr. Rex, _Bot. Gaz._, XIX., 398, compares the present species with _C. minutissima_, and _C. tenella_ with _C. dictydioides_; which is correct for the American presentation of the species named. _C. dictydioides_ is certainly our presentation of _C. intricata_, a geographic species at the least; but if _C. microcarpa_ is purple we have of it no representation; our forms under that name are closely related to _C. tenella_, a yellow-spored species, and might perhaps be there referred; have, however, somewhat larger spores.

12. CRIBRARIA VIOLACEA _Rex._

PLATE XVII., Fig. 8.

1891. _Cribraria violacea_ Rex, _Proc. Phil. Acad._, p. 393.

Sporangia scattered or gregarious, very small, .2 mm. in diameter, violet tinted, erect, stipitate short, about one-half the total height, concolorous, slender, tapering upward; calyculus crateriform, persistent, or marked with minute plasmodic granules; the net rudimentary or poorly developed, the meshes large, irregular, the nodules also large triangular, violaceous; spores pale violet in mass, by transmitted light reddish, 7-8 mu, minutely warted.

A very minute but well-marked species discovered by Dr. Rex in Wissahickon Park, near Philadelphia, otherwise very rare. Lister, however, reports it from England. In minuteness to be compared with _C. minutissima_, from which its color instantly distinguishes it. Dr. Rex reports the plasmodium as "violet black." All our specimens are on very rotten wood, basswood, _Tilia americana_.

Pennsylvania, Illinois, Iowa.

13. CRIBRARIA PURPUREA _Schrad._

1797. _Cribraria purpurea_ Schrad., _Nov. Gen. Pl._, p. 8.

Sporangia gregarious, large, 1 mm. in diameter, dark purple, erect, stipitate, depressed-globose; stipe concolorous, furrowed, about twice the diameter of the sporangium in length, with a distinct hypothallus; calyculus persistent, less than half the sporangium, obscurely ribbed, marked by concentric plications, the margin toothed; the net poorly differentiated, the meshes irregular in form and size, as are also the flat, unthickened nodes, the threads pale, free ends short and not numerous; spore-mass purple; spores by transmitted light, pale or colorless, 5-6 mu, smooth.

Rare. Found on rotten coniferous wood in deep forests. Easily recognized by its large size and uniform purple color. To the next species it offers a general resemblance, but has larger sporangia and an entirely different net. The plasmodium just before the formation of the fruit is scarlet.

Maine, New York, Pennsylvania, Ontario, Oregon, Colorado.

14. CRIBRARIA ELEGANS _Berk. & C._

1873. _Cribraria elegans_ Berk. & Curt., _Grev._, II., p. 67.

Sporangia gregarious, erect or nodding, small, .4-.5 mm., bright purple, stipitate; stipe long, slender, tapering upward, almost black, arising from a scanty hypothallus; calyculus about half the sporangium, finely ribbed, covered especially above with small purple granules, the margin toothed or perforate; net well developed, the meshes small, polygonal, the threads delicate, colorless, with many free ends, the nodules dark-colored, numerous and somewhat prominent; spore-mass pale purple; spores by transmitted light pale violaceous, smooth, 6-6.5 mu.

To be compared with the preceding. The small-meshed net with well-defined, dark-colored nodules is distinctive, aside from the fact of the much smaller sporangia. The stipe is also different, more slender, smooth, and dark-colored. The habitat of the two species appears to be the same. The present species is much more common, ranges farther west, and is to be looked for on the Pacific coast.

New York, Pennsylvania, South Carolina, Missouri, Iowa; Black Hills, South Dakota.

15. CRIBRARIA LANGUESCENS _Rex._

1891. _Cribraria languescens_ Rex, _Proc. Phil. Acad._, p. 394.

Sporangia scattered, very minute, .25-.35 mm., spherical, long-stipitate, drooping; stipe 2.5-3 mm., slender, flexuous, subulate, rugulose; calyculus about one-third the sporangium, reddish brown, shining, minutely striate with granular lines, the margin more or less regularly serrate; net reddish brown, the meshes triangular and the threads simple, the nodes large, polygonal, flat, but well differentiated; the spores when fresh dull red in mass, paling with age; by transmitted light colorless, 6 mu, smooth.

A very singular species, easily recognizable by its long, slender stipes, terminating in exceedingly small spherical sporangia. The colors are obscure, but the striations on the calyculus are violet-tinted, and the reds perhaps predominate elsewhere. "In its scattered and solitary growth, its tall, slender stipes, and relaxed habit it resembles _C. microcarpa_, in its network it approaches _C. tenella_, and its spores have the color of the paler form of _C. purpurea_." So Dr. Rex, _l. c._ Western forms of the first-named species have much shorter stipes; the network in the specimens before us is unlike that of _C. tenella_, but resembles that of _C. purpurea_.

Rare, on very rotten wood, in the forest. New York, Ohio, South Carolina, Ontario.

16. CRIBRARIA CUPREA _Morgan._

PLATE XVII., Fig. 7.

1893. _Cribraria cuprea_ Morg., _Jour. Cin. Soc_., p. 16.

Sporangium very small, .33 mm., oval or somewhat obvoid, copper-colored, stipitate, nodding; stipe concolorous or darker below, subulate, curved at the apex, 2-4 times the sporangium; calyculus about one-half the sporangium, finely ribbed and granulose within, the margin nearly even; the net rather rudimentary, the meshes large, triangular or quadrilateral, the nodules also large, flat, concolorous, the threads slender, transparent, with free ends few; spores in mass copper-colored, by transmitted light colorless, smooth, 6-7 mu.

Recognizable by its small size and peculiar color, that of bright copper, although this fades somewhat with age, and the metallic tints are then lacking. Related to the preceding and in specimens having globular sporangia closely resembling it; but the ground color in _C. languescens_ is always darker, and the stipe proportionally much longer. In habit the sporangia are widely scattered, much more than is common in the species of this genus. Miss Lister, _2nd ed._ regards this as a var. of No. 15.

Comparatively rare. Before us is one very small colony of sporangia from Iowa, one from Ohio, and a large number from Missouri. If one may judge from the material at hand, the favorite habitat is very rotten basswood, _Tilia americana_.

=2. Dictydium= (_Schrad._) _Rost._

Sporangia distinct, gregarious, globose or depressed-globose, stipitate, cernuous; the peridium very delicate, evanescent, thickened on the inside by numerous meridional costae which are joined at frequent intervals by fine transverse threads more or less parallel to each other, forming a persistent network of rectangular meshes.

The ribs or costae of the spore-case radiate from the top of the stipe and unite again at the top of the sporangium in a feeble, irregular net. Schrader, _Nov. Gen. Pl._, p. 11, 1797, applied the name _Dictydium_ to all _Cribraria_-like species in which the calyculus was wanting. Fries follows this, _Syst. Myc._, III., p. 164. Rostafinski, _Versuch_, p. 5, _Mon._, p. 229, first correctly limits the genus and separates it from _Cribraria_. 1873-75.

A single species is widely distributed throughout the world,--

1. DICTYDIUM CANCELLATUM (_Batsch_) _Macbr._

PLATE I., Figs. 6, 6 _a_ and PLATE XIX., Figs. 1, 1 _a_, 1 _b_, 1 _c_, 2, 3.

1789. _Mucor cancellatus_ Batsch, _Elench. Fung._, II., p. 131.
1797. _Dictydium umbilicatum_ Schrad., _Nov. Gen. Pl._, p. 11.
1801. _Cribraria cernua_ Pers., _Syn._, p. 189.
1816. _Dictydium cernuum_ Nees, _Syst. d. Pilz._, p. 117.
1875. _Dictydium cernuum_ (Pers.) Rost., _Mon._, p. 229.
1893. _Dictydium longipes_ Morg., _Cin. Soc. Jour._, p. 17, in part.

Sporangia gregarious, depressed globose, nodding, the apex at length umbilicate, stipitate, in color brown, or brownish purple; the stipe varying much in length from two to ten times the diameter of the sporangium, attaining 5-6 mm., generally erect, more or less twisted and pallid at the apex, below dark brown, with hypothallus small or none; calyculus often wanting, when present a mere film connecting the ribs of the net; the net made up chiefly of meridional ribs connected at intervals by transverse parallel threads, above an open _Cribraria_-like network closing the apex and more or less rudimentary; the spores varying in color through all shades of brown and purple when seen in mass, by transmitted light reddish, 5-7 mu, smooth or nearly so.

This species in the United States is one of the most variable in the whole group. The extremes of such variation might easily constitute types for several distinct species were it not that in all directions the varieties shade into each other so completely as to defy definition. We have before us specimens purple throughout and short-stemmed; purple with stem long, pale and twisted at apex; brown, with the same variations; short-stemmed, with the apex of the stem pallid, and long-stemmed, with and without the same peculiarity. Morgan (_Cin. Soc. Nat. Hist. Jour._, 1893) would set off the purple, long-stemmed forms as _D. longipes_, "stipe three to five times the sporangium," but here are forms in which the stem is ten times the diameter of the sporangium, which yet possess in all other particulars the characters of the short-stemmed forms. European forms also vary. Massee figures one type; Lister, one or two others; Rostafinski's figure indicates a taller form; Fries says, "Stipes elongatus, peridio quinquies et ultra longior." It seems reasonable to suppose that the variation is largely due to atmospheric conditions at the time of fruiting. The purple forms may be cases of arrested development, since the plasmodium appears to be in all cases purple, or at least they seem to represent those plasmodia which have failed of normal ripening. We may recognize two or three general types, distinguished primarily by color:--

a. _D. cancellatum cancellatum._--Sporangia clear brown or with only a purplish tinge, the stipe tapering upward, and in extreme cases perfectly white at the twisted apex. The stipe in length ranges from three to ten times the diameter of the sporangium. The reticulations of the net are generally small and the ribs numerous. This is the most highly differentiated, finished type of the species.

b. _D. cancellatum purpureum._--Sporangium dark, the purple tints predominating, the stipe tapering upward, more or less twisted at the paler, sometimes almost colorless, apex. The stipe ranges a little shorter than in the preceding variety, three to seven times the sporangium. The reticulations of the net are often coarse, the ribs being fewer; the whole structure weak and showing signs of imperfect development.

The figures, 1, 1 _a_, 1 _b_, 1 _c, l. c._, illustrate the ideal accomplishment in form (a). The color is a clear definite brown with no suggestion of purple anywhere. The stipes are three or four times the diameter of the sporangium, brown below, white above, and twisted to allow the sporangium to hang inverted. This is complete in every part; a definite bell-shaped calyx, widening into the cancellate receptacle, the margin constricted, and closed at last by the apical net, _cribrum_, sign of the order.

In form (b), the structure is similar but by no means so symmetrical and complete. The calyx often fails, or is present by obscure indications only. The cancellation is coarser, the number of ribs fewer, the whole sporangium more or less globose; ferruginous or purple, the prevailing tint. Figs. on Pl. 1. are from the ferruginous type.

Figure 3 represents a beautiful thing; cup-less, ellipsoidal, delicate, of average size and in every way well-proportioned, clear rosy brown in color.

This may stand for a third variety; (c) _D. cancellatum prolatum_.

Common everywhere. The fruit appears in June on decaying logs and stumps of various species of deciduous trees, conifers, etc., the finest, and greatest variety, are from southern Missouri.

ORDER IV

=LYCOGALALES=

Fructification aethalioid; peridium membranaceous, tough, simple, without vesiculose with protoplasmic masses, within gelatinous; the capillitium of cortical origin, consisting of irregular lobate or branching tubules, varying much in width, and marked by numerous corrugations, irregular warts or bands; spores minute, ashen or pallid.

This order includes but a single genus,--

=Lycogala= _Micheli._

1729. _Lycogala_ Micheli, _Nov. Plant. Gen._, pp. 216, 217.
1753. _Lycoperdon_ Linn. _Syst. Nat._, in part.
1794. _Lycogala_ Persoon, Roemer, _N. Bot. Mag._, p. 87.

Micheli's description and figures, _Nov. Plant. Gen._, pp. 216, 217, Tab. 95, leave no doubt but that this illustrious man had species of _Lycogala_ before him when he described the genus. His figure 1. no doubt portrays the second species in our present list. More recent writers, from Persoon down, have used Micheli's designation, but differed in regard to the limits to which the name should be applied. It is here used substantially as in 1729. Fries and, after him, Rostafinski make a mistake in quoting Retzius as writing _Lycogala_ (1769). Retzius wrote _Lycoperdon sessile; Kongl. Vetenskaps Acad. Handling, foer Ar._ 1769, p. 254.

=Key to the Species of Lycogala=

_A._ Aethalia irregularly globose.

_a._ Cortex minutely roughened or warted; about
12 mm. in diameter 1. _L. epidendrum_

_b._ Cortex smooth, size large 2. _L. flavo-fuscum_

_c._ Cortex rough; diameter 6 mm. or less 3. _L. exiguum_

_B._ Aethalia conical 4. _L. conicum_

1. LYCOGALA EPIDENDRUM (_Buxb._) _Fries._

1721. _Lycoperdon epidendron_, etc., Buxb., _En. Pl. Hal._, p. 203.
1753. _Lycoperdon epidendrum_ Linn., _Sp. Pl._, p. 1184.
1829. _Lycogala epidendrum_ (Buxb.) Fries, _Syst. Myc._ III., p. 80.

Aethalia solitary or clustered, depressed spherical, or, when crowded, irregular, olivaceous or blackish, minutely warted, 3-10 mm. in diameter, dehiscing irregularly, but more often near the apex; peridium thin, but tough and persistent, made up of numerous agglutinated tubules enclosing in their mashes peculiar cell-like vesicles; capillitium parietal, consisting of long, branching, and anastomosing flattened tubules extended inwardly among the spores, everywhere marked by transverse wrinkles, ridges, and warts, the free ends of the ultimate branchlets rounded, concolorous with the spores; spore-mass, when fresh, rosy, or ashen with a rosaceous or purplish tinge, becoming with age sordid or ochraceous, spores by transmitted light colorless, minutely roughened or reticulate, 5-6 mu.

This is not only a cosmopolitan species, but is no doubt, the most common slime-mould in the world. Found everywhere on decaying wood of all sorts, more particularly on that of deciduous trees. It has likewise been long the subject of observation. It is doubtless the "_Fungus coccineus_" of Ray, 1690, and the type of Micheli's genus as here, 1729. The different colors assumed, from the rich scarlet of the emerging plasmodium to the glistening bronze of the newly formed aethalium, have suggested various descriptive names,--as _L. miniata_ Pers., _L. chalybeum_ of Batsch, and _L. plumbea_ Schum. The peridium is by authors described as double. This is for description only. In structure the outer and inner peridium completely blend. The outer is predominately vesiculose, the inner more gelatinous. For discussion of the microscopic structure see under the next species.

Common. New England, west to Nebraska, South Dakota, Colorado, Washington, Oregon, California; Alberta to Nicaragua.

_Lycogala terrestre_ Fr., _Syst. Myc._, III., 83, appears to be a variety of the present species. In spores and capillitial thread the forms are indistinguishable; the difference is a matter of size, and to some extent, of the color of the wall. The specimens are a little larger, depressed and angular. The peridium is paler, smoother, though sometimes almost black, thin, ruptured irregularly. But the form and color of the peridium in the sporocarps of the older species vary much in response to external conditions; on a substratum affording scant nutrition the forms of fructification are minute; and in all cases, if maturity be hastened, the peridium responds in darker colors. Under more favorable conditions the wall is smoother and brighter.

2. LYCOGALA FLAVO-FUSCUM (_Ehr._) _Rost._

1818. _Diphtherium flavo-fuscum_ Ehr., _Syl. Myc. Berol._, p. 27.
1829. _Reticularia flavo-fusca_ (Ehr.) Fries, _Syst. Myc._, III.,
p. 88.
1873. _Lycogala flavo-fuscum_ (Ehr.) Rost., _Versuch_, p. 3.

Aethalia solitary or sometimes two or three together, large 2-4 cm. in diameter, spherical or spheroidal, purplish-gray or brown, smooth, shining; the peridium thick, simple but in microscopic section showing two or three successive layers; capillitium of abundantly branching, irregular, transparent tubules, marked by numberless warts and transverse rings or wrinkles, spores in mass yellowish gray, by transmitted light, colorless, smooth or only faintly reticulate or roughened, 5-6 mu.

This, one of the largest and most striking of the slime-moulds, is by students generally mistaken for a puff-ball. It occurs on stumps and rotten logs of various sorts in the Mississippi valley, more often affecting stumps of _Acer saccharinum_ L. The fructification, when solitary, about the size of a walnut, though sometimes larger; when clustered, the individuals are smaller. The form depends largely upon the place in which the fruit is formed. The plasmodic mass is so large that its form is determined by gravity. Thus on the lower surface of a log raised a little distance from the earth the aethalium is often pyriform. This fact did not escape Micheli. See _Nov. Plant. Gen._, Tab. 95. The plasmodium is pale pink, soon becomes buff when exposed in fruiting, finally pallid or somewhat livid, and is outwardly changed into the stout, tough peridium. This consists of an intricate network of irregular gelatinous tubules enclosing within the meshes protoplasmic masses of pretty uniform size, 60-100 mu. Outwardly the protoplasmic vesicles predominate; inwardly the gelatinous tubules, which are, in some instances at least, continued toward the centre of fructification to form the capillitium. The protoplasmic masses referred to respond to ordinary stains, are often broken into numberless small cells corresponding in size and appearance to ordinary spores.

Not common. New England, Ohio, Iowa. Perhaps more abundant in the Mississippi valley; Canada.

3. LYCOGALA EXIGUUM _Morg._

1893. _Lycogala exiguum_ Morg., _Jour. Cin. Soc._, p. 8.

Aethalia small, 2-5 mm. in diameter, gregarious, globose, dark brown or black, sessile, minutely scaly, irregularly dehiscent; the peridium thin, the vesicles comparatively few, in irregular patches which are more or less confluent; capillitium as in preceding species, the tubules slender and branching; spore-mass pale, ochraceous, spores by transmitted light colorless, almost smooth, 5-6 mu.

Found in the same situations as No. 1, and at the same season. Recognizable by its _gregarious_ habit, not crowded nor superimposed, small size, and dusky color. The little spheres occur a dozen or more in a place, dark lead-colored, shading to black, opening rather regularly at the top. It looks like a depauperate _L. epidendrum_, but seems to be constantly collected.

Our specimens are from Ohio, Iowa, Missouri, Canada.

4. LYCOGALA CONICUM _Pers._

1801. _Lycogala conica_ Pers., _Syn. Fung._, p. 159.
1875. _Dermodium conicum_ (Pers.) Rost., _Mon._, p. 284.

Aethalia scattered, sometimes two or three together, small 2-4 mm. high, conical, sessile, pallid, grayish brown, marked by obscure black reticulations, opening regularly at the somewhat acuminate tip; peridium thin in structure, as in _L. epidendrum_, but more delicate; capillitium made up of abundant, slender, uniform threads almost smooth, simple, the free ends obtuse, taking origin in the cortex much as in the preceding species; spores in mass ochraceous, by transmitted light colorless, minutely warted or faintly reticulate, about 5 mu.

A very distinct and rare little species. Well described by Persoon, who also appears to have observed the plasmodium "_primo rubra_." The color of the mature form varies with age; at first somewhat purplish. Dr. Rex collected it in Pennsylvania; Mr. Morgan has it from Ohio; our specimens are from southeastern Missouri.

ORDER V

=TRICHIALES=

Fructification sporangial, rarely plasmodiocarpous, the sporangia stalked or sessile, gregarious or closely crowded, limeless throughout; the capillitium of definite threads, free or attached to the sporangial wall, isolated or combined into a net; spores generally some shade of yellow, never purple or black.

The distinguishing feature in this order is found in the peculiar sculpture of the capillitial threads. This is suggested by the tubules of _Lycogala_, though probably the resemblance is superficial only. The individual threads, as in _Trichia_, are called elaters, from their probable efficiency in spore-dispersal.

As here limited, the order is coextensive with the _Calonemeae_ of Rostafinski, except that that includes in addition the genera _Prototrichia_ and _Dianema_. The course of differentiation may be assumed to start with _Dianema_, through the _Perichaenaceae_ to the _Arcyriaceae_ and again from the same starting-point through _Prototrichia_ to the _Trichiaceae_.

=Key to the Families of the Trichiales=

_A._ Capillitial threads transverse to the sporangial
cavity, attached usually at each end, plain or
only slightly roughened _Dianemaceae_

_B._ Capillitium plain, papillose, or spinulose, often
scanty, not netted, the threads sometimes
attached by one end to the sporangium wall _Perichaenaceae_

_C._ Capillitium a distinct net, usually attached
below to the sporangial wall; sculpture
various, not continuous spiral bands _Arcyriaceae_

_D._ Capillitial threads transverse, fascicled,
attached at both ends, but sculptured by well
defined spiral bands _Prototrichiaceae_

_E._ Capillitial threads typically free, sometimes
more or less branched, forming a loose net
attached below, characterized by definite
spiral bands, or sometimes by scattered rings _Trichiaceae_

_A._ DIANEMACEAE

=Key to the Genera of the Dianemaceae=

_A._ Capillitial threads attached at one end, or free 1. MARGARITA

_B._ Capillitial threads attached at each end 2. DIANEMA

=1. Margarita= _List._

1894. _Margarita_ Lister, _Mycet._, p. 203.

Sporangia sessile, the capillitium simple, hair-like, coiled.

1. MARGARITA METALLICA (_Berk. & Br._) _List._

PLATE XVII., Figs. 1, 1 _a_, 1 _b_.

1838. _Physarum metallicum_ Berk. & Br., _Mag. Zool. & Bot._, I.,
p. 49.

Sporangia scattered or clustered, globose, or somewhat plasmodiocarpous, .5-1 mm., sessile, coppery iridescent, the peridium thin, opening above irregularly; capillitium of long flexuous, coiling, simple or little dividing threads, nearly smooth, with infrequent attachments to the peridial wall; spores in mass yellowish, transparent under the lens, delicately verruculose, 10-12 mu.

One of the handsomer species of the present group. So far a Pacific coast form. California, Oregon, Washington; reported from Chile.

=Dianema= _Rex_

1891. _Dianema harveyi_ Rex, _Proc. Phil. Acad._, p. 397.

Sporangia simple or plasmodiocarpous; capillitium composed of threads without characteristic thickenings running entirely across the sporangium attached both to the base and to the opposite wall, not joined to form a network.

=Key to Species of Dianema=

_A._ Sporangia distinct, iridescent 1. _D. harveyi_

_B._ Fructification more or less plasmodiocarpous,
dull brown 2. _D. corticatum_

_C._ Sporangia, some of them stipitate 3. _D. andersoni_

1. DIANEMA HARVEYI _Rex._

PLATE XVI., Figs. 5 and 5 _b_.

1891. _Dianema harveyi_ Rex, _Proc. Phil. Acad._, p. 397.