100 MR. J. GROVES ON CHAROPHYTA 
prime) prolata, sæpe conjuncta. | Oogonia solitaria, ovoideo-ellipsoidea, long. 
(coronula exclusa) c. 325 p, lat. c. 2654; coronula alt. c. 30 a, lat. 60 a, per- 
sistens. Oospora subrotunda rubro-brunnea atra, long. 225-230 u, lat. 200— 
220 u, crass. c. 125 a, liras humiles sed conspieuas 7-8 exhibens, non cristata ; 
membrana subtiliter et hebete granulata. Antheridia diametro c. 225 y. 
Moratuwa, between Colombo and Galle, West. Prov., Nov. 1895, no. 12. 
A slender, graceful plant, probably attaining a height of about 80 em., with 
long internodes, resembling in habit an extended form of N. gracilis, but 
with firmer rays, the dactyls uniformly 2-celled, straight and rigid, 
resembling those of N. tenuissima. I have not seen a specimen of 
N. gracillima, Allen, but from the author's description and plate, N. lepto- 
dactyla would appear to resemble it in habit and in the long cylindrical 
dactyls, but to differ in the size of the fruit, the character of the ridges on the 
oospore, and the decoration of its membrane. It differs from N. mucronata 
and the near allies of that species in habit, the number of secondary and 
tertiary rays, the sterile first node, the size of oospore, &e., and from that 
species and N. pseudo-flabellata in the comparative length and tenuity of its 
dactyls and the decoration of the oospore-membrane. The uniform length 
of the dactyls as well as their tenuity distinguish it from the subbrachy- 
dactylous series, which includes N. oligospira, N. orientalis, and N. expansa. 
NITELLA MUCOSA, sp. nov. N. pseudo-flubellata, Braun, forma mucosa, 
Nordst. in Act. Univ. Lund, xvi. 1v. (1880) p. 16. 
Panadura (at sea-level), West. Prov., 16th Nov. 1895, no. 14 ; Moratuwa, 
Nov. 1895, no. 13 ; shallow tank, Tangalla, 8th Jan. 1898, no. 32 ; Dikwella, 
9th Jan. 1898, no. 33; Amblangoda, South Prov., 12th Jan. 1898, no. 34. 
Resembling N. pseudo-flabellata in the proportionate length of the primary 
ray and in the number of tertiary rays, but differing from that species in 
having the fruiting whorls enveloped in thick mucus and from the typical 
forms thereof at least in the granulate oospore-membrane. The size of the 
oogonium and oospore is variable. In the description of the type plants 
collected by Dr. Berggren in New Zealand the dimensions of the latter are 
given as, length 300-320 y, breadth 285-300 u. In the more robust plant 
collected by Cheesman, also from New Zealand, the oospores are about 
350 y long, 325 u broad. The oospores of the Ceylon plants measured, except 
no. 13, range from 250-300 u long, 225-250 u broad, while those of no. 13 
are only about 200 w long and 175 a broad. 
N. OLIGOSPIRA, Braun in Monatsb. Akad. Berl. 1858, p. 357. 
Dambool, Nov. 1895, nos. 15 & 16 ; Tirupane, 8th & 9th Nov. 1895, no. 17: 
shallow tank, Tangalla, 8th Jan. 1898, nos. 35 & 36. 
This variable and rather indeterminate species seems to occupy an 
intermediate position between the sections Macrodactylæ and Brachydactylæ. 
