Fam? 
FIL A die ic to the Freshwater Alge of Ceylon. By W. West, F.L.S., and 
G. S. West, B.A. F.L.S., Hutchinson Student of St. Johws College, Cambridge, ` 
Professor of Natural History, Royal Agricultural College, Cirencester. 
(Plates 17-22.) 
Read 20th June, 1901. 
A CERTAIN amount of work has been done on the Algæ of the various British 
possessions which constitute the Indian Empire, but the freshwater Alge of the island 
of Ceylon have up to the present been almost completely overlooked. Contributions to 
the Alga-flora of Northern India, more particularly of Bengal, have been published by 
G. C. Wallich (1860), Lagerheim (1888), and W. B. Turner (1893); and a paper has also 
appeared on “ Burmese Desmidiez ° by Joshua (1886). 
A few Algz from Ceylon have been issued in Wittrock and Nordstedt's * Algæ Ex- 
siccatæ, but, so far as we know, the only freshwater ones are Pithophora polymorpha, 
Wittr., and Strogonium ceylanicum, Wittr. Gomont, in his * Monographie des Oseil- 
lariées " (Ann. Sci. Nat. 7"* sér. xvi. 1892, p. 98-99), records Plectonema Wollei, Farlow, 
from * insule Ceylon: (Grunow in herb. Thuret)”; and Grunow, in his “ Alge” in 
the * Reise der Novara,’ 1870, p. 40, describes Cladophora clavuligera, a minute species 
occurring attached to freshwater snails in the island of Ceylon. Also, in a recent paper 
by Borge, entitled ** Ueber tropische und subtropische Süsswasser-Chlorophyceen ” (Bih. 
till K. Sv. Vet.-Akad. Handl. Bd. xxiv. 1899, Afd. 3, no. 12), he mentions the following 
six species from Ceylon :— Closterium parvulum, Naeg.; Cosmarium Botrytis, Menegh. ; 
C. punctulatum, Bréb. ; C. holmiense, Lund.; C. subspeciosum, Nordst. ; and Staurastrum 
punctulatum, Bréb. Curiously enough, all the six are common European Desmids. In 
addition to the above there is one species—Hassallia ceyloniea—described by Schmidle 
in * Hedwigia, Bd. xxxix. 1900, p. 185, as occurring in Ceylon “am Mont Lavinia bei 
Colombo." 
The Algse which form the subject of this memoir were obtained from material 
collected by Mr. W. G. Freeman, B.Sc., PLS, in the island of Ceylon in 1896-97. He 
kindly placed at our disposal some filty tubes of this material collected from very varied 
localities in the island. Representatives of almost all the families of freshwater Algve 
were obtained, and two of the collections were somewhat rich in Desmidie:ze. 
The Desmids observed were essentially tropical in character, and present great 
similarity to those of Northern India, Burmah, and even Singapore and some of the 
East Indian Islands, a considerable percentage of the species being identical with Indian 
and Burmese forms. One striking feature is the presence in Ceylon of a relatively large 
SECOND SERIES.—BOTANY, VOL. VI. T 
