( 2 ) 
often densely tufted when young. Leaves 3-4-divided, termi¬ 
nals very slender, of variable length (elongated or very short) ; 
oogonia one (or two) at a node ; coronula short and small, but 
the apical cells much longer than the sub-terminal, which are 
small and disk-shaped. Antheridium 275 in diameter, oospore 
306 to 340 long by 270 broad (in our specimens immature). 
8. Plant 8 to 10 inches high, very slender, with remote verti¬ 
cils (spreading), consisting of 6 to 8 leaves. Leaves diarthro- 
dactylae, four times divided, terminating in a mucro ; the ultimate 
segments unequal, at times elongated and slender, at times quite 
short (brachydactylae) ; the leaf 200 diameter, the first segment 
156, the second (102) to 150, the third (88) to 95 in diameter, 
the mucro 55 to 60 long. 
Oogonia clustered (2 to 3) at the nodes of the leaves, coro¬ 
nula not elongated, cells connivent, 60 broad, 48 high, and 
oospore 272 to 306 long, 170 to 240 broad; (measurements of 
several mature oospores, give length and breadth as follows, 340 
by 292, 353 by 306, 360 by 292, 368 by 292, 368 by 306, 368 
by 319); with 8 rather blunt ridges, rarely 7 or 9; surface 
minutely roughened with granules, which are quite coarse and 
more prominent at one or two points on the shell, usually near 
the apex. 
9. Plant very delicate, often minute, 3 to 4 inches long ; leaves 
3-4 divided ; stem diameter 102, leaf first node 75, second 60, third 
36, fourth 34, mucro 70 long, very slender. Antheridia only 75 
in diameter; oogonia clustered, oospore 272 to 306 long, 170 to 
240 broad ; surface too immature to examine. This plant occurs 
very sparingly among the collections of number 8, which I have 
received ; it is probably a reduced form of that species ; its ex¬ 
treme delicacy is shown by the measurements of stem and leaves. 
These forms 7, 8 and 9 belong to the section Polyglochin or 
diarthrodactylae—brachydactylae—subdivision of Nitella. The 
oogonia being clustered (not isolated at the nodes of the leaf) 
place the species near the three American sub-species, microcarpa 
A. Br., Glaziovii Zell, and megacarpa Allen, all doubtless forms 
of one species for which microcarpa , the oldest name, is very in¬ 
appropriate. These species as well as oligospira possess oospores 
