Sumstine: North American Hyphomycetes 55 



This genus bears some resemblance to Rhinotrichum as the 

 author states : " It is Rhinotrichum but with inflated basidia 

 which are constricted at the point of union with the hyphae." In 

 the original description the irregular spore-bearing processes are 

 called basidia but to me the term sterigmata seems more ap- 

 propriate. 



Key to the Species 

 Spores very irregular. i. O. carpophilum. 



Spores regular or nearly so. 2. O. macrbsporum. 



i. Olpitrichum carpophilum Atkinson, 1. c. 

 Stratum thin, white, or slightly colored ; hyphae branched, sep- 

 tate, creeping, 5-8 jjl thick; fertile branches erect, simple or 

 branched, septate, bearing at the apex flask-shaped, fusoid, or 

 enlarged processes (sterigmata) irregularly scattered or grega- 

 rious ; spores ovoid-oblong, hyaline or pale-colored, irregular, 

 13-16 X 18-30/*. 



On Gossypium herbaccum. 



Specimens examined: Alabama, Atkinson (type). 



The spores are exceedingly variable in shape and size. Very 

 irregular bodies are developed on some of the fertile branches. 

 The real nature of these bodies is not known. A careful exami- 

 nation did not reveal anything that resembled sterigmata. 



I am indebted to Professor Atkinson, of Cornell University, 

 for a slide of the type material. 



2. Olpitrichum macrosporum (Farlow) 

 Rhinotrichum macrosporum Farlow ; Sacc. Michelia 2 : 148. 1880. 



Stratum effused or pulvinate, sordid-white ; hyphae branched, 

 septate, 8 fx thick; fertile branches erect, remotely septate, slightly 

 colored, bearing near the apex irregular or sometimes branched 

 processes (sterigmata) ; spores ovoid or obovoid, smooth, hyaline 

 or slightly colored, 16 X 30-35 



Specimens examined: Louisiana, Ellis Collection 1653. 



The specimens in the Ellis collection were evidently commu- 

 nicated by Dr. Farlow and in all probability are part of the orig- 

 inal collection. 



The principal difference between the two species is in the form 

 of the spores. When more and better material is studied these 

 two species may prove to be the same. 



High School, 



Pittsburgh, Pa. 



