In the crevices and on the inside of bark of fallen logs of various sorts, walnut, maple, etc.

Not commonly collected. Specimens are before us from New England, Illinois, Iowa, Missouri, Florida, Mexico, Nicaragua. Probably over the whole wooded region of the continent.

2. Perichaena quadrata Macbr.

Sporangia very small, less than ½ mm., crowded, polygonal or quadrangular, depressed, but not flattened, smooth, bright rufous or brown; the peridium rather thick, yellow within, the dehiscence circumscissile; capillitium scanty, of slender, sparingly branched filaments, the surface minutely roughened, warted or spinulose; spore-mass yellow; by transmitted light pale yellow, 9–11 µ.

Differs from the preceding by the much smaller size of the sporangia, different color and habit. The sporangia, while depressed, still maintain considerable rotundity; they are occasionally quite spherical, and then of very uneven size, hardly in contact. In some cases the plasmodium before maturing seems to assume the form of a plasmodiocarp, which, by transverse fission at intervals, forms the curious four-sided conceptacles. At other times the plasmodium assumes the shape of a flat cushion or plate, which then subdivides into minute polygonal segments. This form has been known some years to collectors, and, if named at all, has been called P. irregularis. Lister, l. c., assures us that Berkeley's type "is typical P. depressa."

Not common. Pennsylvania, Ohio, Illinois, Missouri.

3. Perichaena corticalis (Batsch) Rost.

[Plate II]., Figs. 1, 1 a, 1 b.