PERICH^NA 257 



Easily recognized by the peculiar polygonal, depressed-flattened 

 sporangia and consequent shallow spore-cases in which lie the yellow 

 spores and scanty capillitium. 



In the crevices and on the inside of bark of fallen logs of various 

 sorts, walnut, maple, etc. 



Not rare but not commonly collected. Probably over the whole 

 wooded region of the continent, and widely distributed in temperate 

 and tropical regions generally. 



2. Pericilena quadrata Macbride 



N. A. Slime-Moulds ed. 2. 243. 1922. 

 PI. XVII, Figs. 435, 436, 437, 438. 



Sporangia very small, 0.1 to 0.4 mm. in diameter, crowded, polyg- 

 onal, depressed but convex, smooth, bright rufous or brown to nearly 

 black; peridium rather thick, yellow within and minutely papillose, 

 the dehiscence circumscissile; capillitium usually scanty, of slender, 

 sparingly branched filaments, 2-3 n thick, the surface minutely 

 roughened; spore-mass yellow; spores by transmitted light pale yellow, 

 minutely spinulose, 9-11 fx. Plasmodium yellow, then maroon. 



Differs from the preceding by the much smaller size of the sporangia 

 and the 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 long been known to 

 collectors, and has often been distributed as P. irregularis Berk. 

 & Curt. Lister assures us that Berkeley's type "is typical P. 

 depress a." 



Not common. Pennsylvania, Ohio, Illinois, Missouri, Iowa. 



3. Perich^ena corticalis (Batscti) RosL 



Mon. 293. 1875. 

 PL XVII, Figs. 439, 440. 



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



1791. Sphtzrocarpus sessilis Bull., Champ. 132, pi. 417, fig. 5. 



1794. Trichia fusco-atra Sibth., Fl. Oxon. 407. 



1796. Trichia gymnosperma Pers., Obs. Myc. 1 : 63, pi. 6, figs. 1, 2. 



1797. Trichia circumscissa Schrad., Nov. Gen. PL 19. 



