22 Setchell. — An Examination of the Species 
The general habit is not striking ; but is, in a certain way 
at least, distinctive. The size and structure of the sorus is 
found in no other species. The central portion of compact, 
fine hyphae, and the peculiar shape of the cortical cells would 
distinguish it at once from any other known form. Finally, 
the germination is different in its details from any other 
which has yet been obtained. It is considered as the type 
of a subgenus, P seudodoassansia. 
Season. D. obscura seems to be an autumnal species. It 
has been collected in Connecticut in the, early part of Sep- 
tember, apparently young, and, in the latter part of September 
and in October, it has been found mature in Massachusetts. 
Distribution. Probably a wide-spread species in the 
United States, but escaping detection on account of being so 
inconspicuous. I have found it at Norwich, Conn., and at 
Medford and Cambridge, Mass. 
Doassansia occulta [Hoff mi), Cornu. 
What appears to be the Sclerotium occultum of Hoff- 
mann’s leones has been re-discovered in America. Professor 
Farlow has kindly allowed me to examine the original speci- 
mens of D. Farlowii , Cornu, which were collected by James 
Fletcher at Ottawa, Canada, and portions of which were sent 
to Woronin and to Cornu. A form inhabiting the ovaries of 
Potamogeton Claytonii (P. P ennsylvanicus , Chami) has been 
collected by myself at Norwich, Conn., in some abundance. 
The distortions produced by these two sets of specimens 
appear very much alike and agree well enough with Hoff- 
mann’s figure (Ic. Anal. Fung. Taf. 16, f. 3) ; but there are some 
differences in the spores between the two sets of forms, and 
therefore it has seemed better to describe them separately. 
My own specimens agree best with Hoffmann’s figure of 
a cross-section of a sorus (1. c.), and therefore, for the present, 
they will be regarded as identical with the type of the species, 
while Fletcher’s specimens will be described as Var. Farlowii . 
Type. This form affects the ovaries of Potamogeton Clay- 
