504 MR. JAMES GROVES : 
1. NITELLA Agardh. 
I. Homceocleme. 
i. Anarthrodactyle. 
1. N. MIRABILIS Nordstedt, species nova. (Pl. 35.) 
Homeeoclema anarthrodactyla semel furcata (glæocephala ?) dicecia. 
Oogonia et antheridia utræque aggregata plerumque longipedicellatæ ; 
dactyli + mucronati. 
Dicecious. Stem rather slender, diam. c. 5004. Whorls of 6-8 long 
branchlets. Branchlets once-furcate, the primary rays averaging about 3 
the length of the entire branchlet ; dactyls 2-4, usually 3, long, slender 
(diam. c. 125), equal, divergent, terminating in + mucronate points. 
Oogonia usually clustered 2-3 together,a few solitary, conspicuously stalked, 
c. 550-700 u long (excl. cor.), 475-575 u broad ; spiral cells swelling slightly 
at their apex, usually showing 8 convolutions; coronula broadly conical, 
e. 90 u high, 75 u broad, deciduous. Oospores c. 375-475 y long, 325-375 u 
broad, e. 300 u thick, deep golden-brown, showing 6 thin broadly-flanged 
ridges ; membrane finely granulate. Antheridia clustered 2-3 together, 
central (when present) sessile, the lateral stalked, diameter c. 500-600 a. 
In some shallow pools in the bed of an ancient river, Gonda, Oudh (Dist. 6). 
14 Jan. 1922, no. 1; Dec. 1923, nos. 21,23. 6. O. Allen. 
This remarkable species was first discriminated by Dr. Nordstedt, who 
gave it the ms. name N. mirabilis, from specimens collected in Yunnan, 
China, 29 April, 1908, by Fr. Ducloux (no. 5856), which are preserved in 
the national herbarium in Paris. Dr. Nordstedt kindly afforded my late 
brother and myself the opportunity of examining the specimens, and has 
asked me to describe the plant. 
Mr. Allen's discovery of it in India is of great interest, and his earefully 
selected. and admirably prepared specimens have supplied the means of 
describing the habit of the plant and of figuring it, the original Chinese 
specimens being poor. The Indian specimens show a rather small plant, 
about 15-20 cm. in height, with long branchlets, and a generally lax habit 
resembling that of the European N. syncarpa, the male plant forming small 
dense heads. The stem and branchlets show well-marked annular inerus- 
tation. The Chinese plant has rather larger oogonia and oospores than that 
from India. The very young fertile heads of both plants appear to be 
enveloped in a slight mucous cloud. 
The outstanding features of the species are the clustered long-stalked 
oogonia and the antheridia in clusters of 2-3, some with conspicuously long 
stalks, originating laterally in the same manner as the dactyls, one being 
usually sessile in its normal position. The stalks of the oogonia are some- 
times extremely long ; I have measured one of about 5 mm. 
