1 84 THE NORTH AMERICAN SLIME-MOULDS 



well developed, of slender yellow threads of various widths, 

 almost smooth; spores minutely warted, 10-12 p. 



Easily recognized by the peculiar, polygonal, depressed- 

 flattened sporangia and consequent shallow spore-cases in 

 which lie the yellow spores and scanty capillitium. Rostafinski 

 refers here P. vapomria Schw., No. 2311, but the meagre 

 description seems rather to apply to the next species. The 

 original material is no longer accessible. 



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. PERICH^ENA QUADRATA Macbr. n. s. 



1893. Perichtzna irregularis Berk, and Curt., Morgan, Jour. Cm. 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 dehis- 

 cence circumscissile ; capillitium scanty, of slender, sparingly 

 branched filaments, the surface minutely roughened, warted, or 

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

 yellow, 9-11 //.. 



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 occa- 

 sionally 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, /.<:., 

 assures us that Berkeley's type "is typical P. depressa." There 



