Robinson . — Notes on the Genus Taphrina . i 73 
from the ascus, resembling, except in its more slender form, 
one of the rootlike appendages which are really developed 
downward from the asci of T. aurea and T. caerulescens ; but 
its different nature becomes clear when its connection can be 
traced with the mycelium below. From the position of its 
mycelium and the mode of forming its asci, it is evident that 
this species is closely related to T. Potentillae , just described, 
however dissimilar it may seem in the size and shape of the 
asci themselves and the spores they contain. 
T. ALNITORQUA, Tub, in Ann. des Sciences Nat., ser. 5, 
Tome v. p. 130. 
Ascomyces Tosquinetii , Westendorp, in Bull, de f Aca- 
demic royale de Belgique des sciences, ser. 2, Tome xi. 
p- 655. 
Exoascua A Ini, De Bary. 
Exoascus alnitor quits, Sadebeck, Untersuchungen liber 
die Pilzgattung Exoascus , p. 1 15. 
This species is common in Massachusetts on the bracts of 
the fertile catkins of the alder. It develops a month or two 
earlier than the other Taphrinae , and, although easy to find, 
it is for some reason seldom in good condition for microscopic 
study. The bracts which are attacked grow abnormally long 
and thick, are variously curled and twisted, and become hoary 
with the escaping spores. The asci are borne on all parts of 
the infected bracts ; they are 29-37 jx long and 6-10 \x thick. 
Although, as these measurements show, there is considerable 
variation in the length and thickness of the asci, I fail to find 
here the dimorphism mentioned by Johanson in the asci of 
this species in Sweden. Each ascus is furnished with a cylin- 
drical stalk-cell 15-17 ^ high and 6-8 /x thick. The spores are 
usually eight, sometimes many, spheroidal in form, and 3 J-6 fx 
in diameter. 
In Europe T. alnitor qua has a form which occurs on the 
leaves of the alder, and, although not yet found in America, 
this form may well be looked for, as it is not improbable that 
it occurs here also. 
