538 
Anew Species of Nitella, belonging to the N, flexilis Series, with a 
Review of the allied Species. 
By T. F, ALLEN. 
( PLATE 284. ) 
NITELLA LAXA n. sp. 
Lunitella, monarthrodactyla, furcata, homocophyla, gymocarpa 
monoica, apiculata. 
Plants as long as thirty cm., or longer, diffusely branched, 
very flexible and translucent, bright green, of the habit and appear- 
ance of WV. flexilis. Stem 500 y» in diam., verticils remote, becom- 
ing. crowded above, of eight leaves. Leaves of lower sterile 
verticils long and flexible, once divided into two to four terminals. 
Leaves of the upper fertile verticils shorter, but still longer than 
the internodes, once divided ; leaves vary from 300 to 430 win 
diam., once divided; terminals, one or two when fertile, two to 
four when sterile, one-celled, apiculate, about 250 in diam. 
Antheridia and oogonia single on the nodes of the leaves, the 
latter distinctly -stipitate; coronula evanescent. Antheridium 
usually about 350 in diam., closely sessile. Oospore, 410 to 485 
long, 400 to 460 broad with six prominent ridges ; membrane covered 
with a thick close felt ( grumous), yellowish red (usually mot- 
tled with red). 
Collected in Yakushiji pond, Kyoto, Japan. (Plate 284.) 
This species adds another to the “ flexilis” group, which may 
be classified at present as follows: 
XV. flexilis, spore membrane smooth. 
NV. Californica A. ) 
NV. Mexicana A.S 
V. /axa A., spore membrane grumous. 
Considered as to size. 
NV. Mexicana, a large coarse plant, has the smallest oospores, 
275 long, with 5 prominent ridges. _ 
N. flexilis, oospores 425, with 6 or 7 thin and sharp ridges mod- 
erately prominent. : 
J. laxa, oospores 485, with 6 prominent ridges. 
N. Californica, oospores 585, with 6 or 7 thin and sharp ridges, 
oa 
spore membrane granular. 
, a 
