1896.] Aquatic Fungi. 323 
the result of a definite pressure by which the wall becomes 
distinctly indented. The species previously described (5; 
Reinschit) has been observed by the writer in great abundance 
and in perfect condition since the publication of the note above 
mentioned, and in specimens growing under favorable condi- 
tions the emission of the zoospores has been seen to be simi- 
lar to that of Rhipidium except that the membrane surround- 
ing the emerging spore mass is ruptured almost immediately, 
sothat all but a small number of the spores escape in the 
sual way through the open mouth of the sporangium. In 
this genus the zoospores are like those of the Saprolegnie 
lM general appearance, and are quite unlike those which have 
jist been described as occurring in Rhipidium. 
If we compare these characters with what few data are avail- 
able concerning Rhipidium elongatum it is apparent that, 
though we know nothing as to its type of branching, it 
strikingly resembles the species of Sapromyces in other essen- 
tal points. Its antheridial branch ‘‘présente presque invari- 
; "courbé: c’est par ce bec seulement qu'elle touche : 
Sgone.”® Again ‘le point ou se fixe lanthéridie semble 
Leen constant: c'est vers le sommet chez R. elongaium. 
y 
® patoi de loogone, et finit par la perforer comme par suite 
Ue pression considerable (RAzpidium elongatum). ad 
NOW we examine the characters of the genus rian 
it Mas Araiospora, it is apparent that it represents a Ces 
ge form between Rhipidium on the one hand and n> # 
Sg n the other. In general habit it resembles Rhipidiu 
¥e have . - +47. while its type of 
Seen dium; while 1 
atchin » Is not the case in Rhipi , wht reespoird 
*xact| as 
Y to those of Sapromyces. The oogonia, however, 
;Comn, Mon 
: ° 
10. cit. 31. gtaph 209, note. 
