The very minute sporangia, 3 mm., of this species cause it to be overlooked generally by collectors. Nevertheless, it may be found on decaying soft woods, in August, probably around the world. The number of sporangia produced by one plasmodium is in Iowa also small. The larger specimens might be mistaken for species of _Perichaena_, but are easily distinguished by the regular and lobate dehiscence. The plasmodium is yellow. Dr. George Rex, in almost the last paper from his hand, gives an interesting account of this diminutive species. Among various gatherings studied he found a black variety, a melanistic phase, so to say, and was able to follow the evolution of the sporangia from the yellow plasmodium. The sutures by which the peridium opens, first show signs of differentiation by change of color from yellow through garnet to black. Later the entire wall undergoes similar color changes, beginning next the completed sutural delimitations. Of the open peridia, the reflexed segments remind one of certain didermas, as _D. radiatum_. See _Bot. Gaz._, Vol. XIX., p. 399. New England, New York, Pennsylvania, Iowa. 4. LICEA PUSILLA _Schrader._ 1797. _Licea pusilla_ Schrad., _Nov. Gen. Pl._, p. 19, tab. VI., f. 4. 1829. _Physarum licea_ Fries, _Syst. Myc._, III., p. 143. 1875. _Protoderma pusilla_ (Schrader) Rost., _Mon._, p 90. Sporangia scattered, gregarious, depressed-globose, sessile on a flattened base, dark brown, shining, .5-1 mm.; peridium thin, dark colored, translucent, dehiscent above by regular segments; spore-mass almost black, spores by transmitted light olivaceous brown, smooth, or nearly so, 15-17 mu. Fries, _l. c._, makes this a physarum, and argues the case at length, evidently with such efficiency that he greatly impressed Rostafinski, who did not make it a physarum indeed, but actually gave it generic place and station of its own; a physarum may do without calcium in the capillitium perhaps, but not be entirely non-calcareous; so he writes _Protoderma_ (first cover) and places the species number 1 on the long list of endosporous forms. Even in his '_Dodatek_', or supplement, as we should say, he refers to the thing again, but only to correct the inflexional ending of the specific name; he writes _Protoderma pusillum_ (Schrader) Rost! Schweinitz reports the species for America and Morgan cites Schweinitz and reports it for Ohio, but we find it in no American collections. _B._ ORCADELLACEAE; Sporangia distinct, minute, long stipitate, opening above by a distinct lid. A single genus,-- =Orcadella= _Wingate_ 1889. _Orcadella_ Wingate, _Proc. Phil. Acad._, p. 280. Sporangia furnished with rigid, unpolished stipes, blending above with the substance of the thick unpolished walls; the operculum thin, delicate, membranaceous. A single species,-- 1. ORCADELLA OPERCULATA _Wingate._ PLATE XII., Fig. 11. 1889. _Orcadella operculata_ Wingate, _Proc. Phil. Acad._, p. 280.