with 7—9 ridges. The surface of the spore seems to have a super¬ 
ficial and dense grumous layer of felted fibres, covering a granu¬ 
lated surface, but the granules are not pointed and do not pro¬ 
trude through the felted layer. 
This species seems to me to belong rather to the macrodacty- 
lae division, and to be allied to my new N. exp ansa , to which its 
similar habit of growth associates it. Formerly, owing to the very 
unequal and extremely abbreviated terminals, I referred it to the 
brachydactylae section with which it seems ill-assorted. 
N. orientalis and N. expansa are similar to N. gracilis in habit 
of growth, but the oogonia are clustered and the oospores differ. 
The divisions of the leaf and the character of the terminals also 
separate these two species. The tendency to abbreviate terminals 
and to more than three leaf-nodes in N. orientalis points to a sort 
of transition to the species of the brachydactylae series (which 
abound in Japan). 
Nitella expansa sp. nov. 
Plants 10—12 cm. high, diffusely branched, “bushy;” leaves 
spreading, diffuse, stem 450 in diam. ; verticils approximate, of 
5 or 6 leaves ; leaves spreading, often longer than the internodes, 
3 (rarely 4) times divided ; the first segment less than half the 
length of the entire leaf, 200—265 in diam.; the first node, with 
5 or 6 divisions, usually sterile; the second segment 160-170 in 
diam. ; the second node, with three divisions, fertile; the third 
segment 145—1 5 5 in diameter ; the third node, with 2 or 3 divisions, 
fertile; the fourth segment, 100—120 in diam., usually termi¬ 
nal. The mucro, 34 in diam., 80—100 long ; the terminals are 
unequal, 1—3, often very short; the oogonia are usually isolated, 
but often aggregated on the second and third nodes, not seen 
on the first node, but often found in the verticil, on the stem. The 
antheridia about 200 in diameter; the oospore 245 to 250 long 
by 204 to 220 broad, with five or six sharp ridges, at second and 
third nodes, the surface quite smooth. 
In its aspect it is quite similar to N. gracilis ; the first node of 
the leaf also bears four divisions and is sterile. It is similar to N. 
orientalis in the unequal terminals, one of which is often very short, 
but the second node of this species is 3-times divided and the 
oospore is smaller with a smooth surface (granular in N. orientalis'). 
Collected in “ Shakuhachi-bori water,” Kyoto, Japan. 
