PERICH^NA 243 



England, Illinois, Iowa, Missouri, Florida, Mexico, Nicaragua. 

 Probably over the whole wooded region of the continent. 



2. Perichaena quadrata Macbr. 



1893. Perichaena irregularis Berk. & C, Morgan, Jour. Cin. Soc, p. 20. 



Sporangia very small, less than % 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 fila- 

 ments, the surface minutely roughened, warted or spinulose ; spore- 

 mass yellow; by transmitted light pale yellow, 9-11 /m. 



Differs from the preceding by the much smaller size of the sporan- 

 gia, 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 as- 

 sumes 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, /. 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. 



1783. Lycoperdon corticate Batsch, Elench. Fung., p. 155. 

 1875. Perichaena corticalis (Batsch) Rost., Mon., p. 293. 

 1817. Perichaena populina Fries, Symb. Gast., p. 12. 



Sporangia sessile, gregarious, flattened, hemispherical ; peridia sim- 

 ple, opening by a lid ; dehiscence circumscissile, the upper part chest- 

 nut brown, the lower almost black; capillitium feebly developed, 

 smooth, attached to the lid and usually coming away with it, bringing 

 the brilliantly yellow spore-mass, and leaving a delicate, shining 

 cupule adherent to the substratum ; spores yellow, nearly smooth, 

 10-12 fi. On and under the bark of dead elms of various species. 



