l8 9 1 -] A T orth American Hyphomycetes. 201 



On certain new or peculiar North American 



Hyphomycetes. II. 





Helicocephalum, Gonatorrhodiella, Desmidiospora nov. 



genera and Everhartia lignatilis n. sp. 



ROLAND THAXTER. 



(WITH PLATES XIX AND XX. ) 



Helicocephalum nov. gen. — Sterile hyphae of small diame- 

 ter, aseptate or rarely septate, creeping over the substratum 

 and giving rise to highly differentiated, erect, simple, aseptate 

 sporiferous hyphae furnished with rhizoid like attachments at 

 the base and spirally coiled at the apex: the spiral portion 

 becoming septate and constricted at intervals, its segment- 

 separating at maturity in the form of large, dark colored, 

 thick walled spores. 



Helicocephalum sarcophilum n. sp— Plate XIX, figs. 1-5. 



^ Sterile hyphae hyaline, creeping, branched, 2/i in diameter. 

 Fertile hyphne hyaline, I mm. or more in height, 20-2 5/1 in 

 diameter near the base and 8-10// near the apex: tapering 

 gradually upwards from a slightly swollen base: two or three 

 times abruptly spirally coiled at the distal end, the spiral por- 

 tion of large diameter and converted at maturity into a chain 

 of seldom more than twenty-one spores, by the formation of 

 successive septa. Spores brown, thick walled, with finely 

 granular contents, asymmetrical, usually obliquely truncate, 

 or not evenly rounded, at either end; at first hyaline then 

 brown, 55x30// (maximum 65x35/0, separating and ulti- 

 mately cohering in a viscous, rounded mass. 



On carrion. Connecticut. 



This remarkable form made its appearance on a laboratory 

 culture in company with Cocmansiella spiralis Eidam. It is 

 not gregarious, appearing here and there on the substratum, 

 and closely resembles a large Mortierella or Syncephalis; the 

 piral portion holding a drop of somewhat viscous fluid, which 

 ives it the appearance of a large spherical head (fig. 1). The 

 spores mature simultaneously, falling apart and cohering as 

 shown in fig. 4. They are very thick walled and all attempts 

 to germinate them in nutrient media proved fruitless. 



The relations of this plant are quite uncertain, no fungus 

 Which appears even remotely connected with it being known 

 to the writer. It is placed here among the I Iyphomycete;e 



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