14 Citicinnati Society of Natural History. 



membrane, with a thick dense yellow-brown outer layer of 

 minute scales and granules, becoming darker at the surface, 

 dehiscent in a circumscissile manner. Capillitium of very 

 slender loosely-branched threads, with the surface minutely 

 warted. Spores globose, oval or somewhat irregular, yellow. 

 Distinguished from Ophiotheca by the flattened sporangium 

 with a regular circumscissile dehiscence. 



1. Perich.^;na depressa, Lib. Sporangia very much 

 depressed, polygonal, irregular, crowded, the edges contig- 

 uous, sometimes confluent ; the wall thick, yellow-brown 

 within and scarcely impressed by the spores; the outer sur- 

 face smooth, brown-red to brown or blackish in color, dehis- 

 cent in a circumscissile manner. Capillitium of slender 

 loosely- branched threads, 1-3 mic. in thickness, the surface 

 merely uneven or very minutely warted. Spores globose, 

 yellow, 9-10 mic. in diameter. See Plate I, Fig. 13. 



Growing on the inside of the bark of Juglans, Acer, etc. 

 vSporangia varial)le in size, 7-1.3 mm. in breadth, irregular 

 and angular, much flattened. It is said to include Pcrichccna 

 vapor aria, Schw. 



2. Ferich.^iNA irregularis, B. & C. Sporangia de- 

 pressed, irregular, polygonal, crowded, the edges contiguous 

 and sometimes confluent; the wall thick, yellow inside and 

 faintly reticulately impressed by the spores, the outer surface 

 smooth, purplish-brown, dehiscent in a circumscissile manner. 

 Capillitium of slender-loosely branched threads, about 2 mic. 

 in thickness, the surface mir.utely warted or spinulose. 

 Spores subglobose, yellow, 9-10 mic. in diameter. 



Growing on the outer bark of Acer, etc. Sporangium .5-.6 

 mm. in width, closely crowded and irregular. It is much 

 smaller than Perichccna depressa, and its threads are more 

 distinctly warted and spinulose. 



3. Perich/En.v corticalis, Batsch. Sporangia globose, 

 the base depressed, gregarious: the wall thick, yellow within 

 and distinctly reticulately impressed by the spores, the outer 

 surface reddish-brown or yellow-brown in color, dehiscent in 

 a circumscissile manner. Capillitium of .slender loosely- 

 branched threads, al)out 2 mic. in thickness, the surface very 

 minutely warted. Spores subglobose, yellow, 10-12 mic. in 

 diameter. 



