In 1876, Harkness and Moore collected in the Sierra Nevada Mountains of California, forms of _Diderma_ which are described by Phillips, _Grev._, V., p. 113, as _D. geasteroides_ and _D. laciniatum_. English authorities who have examined the material agree that the forms described constitute but a single species, and Lister makes them identical with _D. trevelyani_ (Grev.) Fr. Rostafinski's figures, 161, 162, are a curious reproduction, evidently, of Fried. Nees von Esenbeck's, Plate IX., Fig. 4. Massee describes a columella; Lister says there is none. What may occasion such divergence of statement none may say; such forms as come in so far from our western mountains have no columella. 17. DIDERMA ASTEROIDES _List._ PLATE XVIII., Figs. 3, 3 _a_ 1902. _Diderma asteroides_ List., _Jour. Bot._, XL, p. 209. 1911. _Diderma asteroides_ List., _Mycetozoa, 2nd ed._, p. 113. Sporangia globose or ovoid-globose, the apex more or less acuminate, sessile, sometimes narrowed at the base to a short, thick stalk, brown or chocolate tinted, marked at the apex by radiant lines, and at length dehiscent by many reflexing lobes revealing the snow-white adherent inner peridium on the exposed or upper side; columella also white, globose or depressed-globose; capillitium generally colorless, somewhat branched, especially above; spores dark violaceous, verruculose, 10-12 mu. Oregon, the Three Sisters Mountains; Colorado; California. A very beautiful species, recognizable at sight; when unopened, by the peculiar chocolate brown, the sporangia smaller than in _D. radiatum_. When opened, the snow-white flower-like figure, flat against the substratum, is definitive. Very near number 16 preceding; the dehiscence more regular. 18. DIDERMA FLORIFORME (_Bull._) _Pers._ PLATE VIII., Figs. 1, 1 _a_, 1 _b_. 1791. _Sphaerocarpus floriformis_ Bulliard, _Champ._, p. 142, t. 371. 1794. _Diderma floriforme_ (Bull.) Persoon, _Roem. N. Mag. Bot._, p. 89. Sporangia crowded, generally in dense colonies, globose, smooth, ochraceous-white, stipitate, the peridium thick, cartilaginous, splitting from above into several petal-like lobes, which become speedily reflexed exposing the swarthy spore-mass, the inner peridium not discoverable, inseparable; stipe concolorous, about equal to the sporangium; hypothallus, generally well developed, but thin, membranaceous, common to all the sporangia; columella prominent, globose or cylindric, often constricted below, and prolonged upward almost to the top of the spore-case; capillitium of slender, delicate, sparingly branched threads; spores dark violaceous-brown, studded with scattered warts, 10-11 mu. Not uncommon, especially on rotten oak logs. Easily recognized by the peculiar form of the fruit, spherical before dehiscence, floriform after. Unlike most species, this form often fruits in dark places, in the interior of a log, even in the ground. New England, Ontario to Iowa and Nebraska, and south.