236 



Mycologia 



of the New York Botanical Garden under these names in order to 

 separate the two species and found no difficulty in making the 

 separation on microscopic characters. Chardon, 1 however, in his 

 recent paper on the Pyrenomycetes of Porto Rico calls attention to 

 the fact that Stevenson in his list of Porto Rican Fungi refers one 

 of his numbers to Herpotrichia albidostoma and the other three to 

 H. diffusa, while all of them agree in spore characters with the 

 former. This is a fair illustration of the confusion which has 

 always existed where determinations are made on superficial exam- 

 ination rather than on a detailed study of the spore characters, 

 although the importance of this kind of work will scarcely be 

 appreciated until one has taken the trouble to make comparative 

 studies of a large number of specimens. Another fact which has 

 been emphasized is the constancy of spore characters in specimens 

 collected over a wide range of distribution including both temperate 

 and tropical species. 



Some of the gross characters common to the two species which 

 are responsible for the existing confusion are: the subiculum of 

 brown mycelium which is usually present but may be entirely want- 

 ing in older or weathered specimens, the light-colored usually red- 

 dish ostiola which are conspicuous but which may become dis- 

 colored with age, and the gregarious or often rather congested 

 habit of growth. The differences in spore characters are: size, 

 form, color and septation. Since these characters, except color, 

 can be shown better by illustration than by description, the reader 

 is referred to the accompanying plate for illustrations of the spores 

 of the two species made from specimens collected over a wide 

 range. 



Both species have been referred to the genus Herpotrichia and a 

 word ought to be added regarding the generic position of Neo- 

 peckia diffusa. In 1912 while working over these specimens in our 

 collections the writer had a rather extended correspondence with 

 Peck regarding the generic position of Herpotrichia rhodospiloides 

 Peck, maintaining that this species belonged to the genus Neo- 

 peckia rather than Herpotrichia. Later study showed this species 

 to be identical with Herpotrichia diffusa which had already been 



1 Mycologia 13: 279-300. 1921. 



