232 Records of the Indian Museum. [VoL. XVIII, 
G. convexiusculus were examined of which three contained examples 
of the parasite. 
Cercaria C (text-fig. 1 /). 
The cercaria is a furcocercous form, similar in most respects in 
its internal anatomy to Cercaria B. It is, however, a much larger 
form and possesses pigmented eye-spots. 
In well-preserved specimens the body is from 188 to 230 p 
in length and from 56 to 80, in breadth, the mean of a number 
of observations being 206 by 70. The undivided part of the tail 
is from 247 to 360,, with mean of 305, and the furca are 
from 106 to 136 », with mean of 120. 
The internal anatomy, so far as it can be made out, is 
very similar to that of Cercaria B; the same gland cells are to 
be seen and in stained specimens the four anterior cells differ in the 
same way from those placed further back. The gonad, however, is 
not crescentic in dorso-lateral view, the acetabulum is smaller and 
the eye-spots are deeply pigmented and black in colour. 
This cercaria was found with the preceding in specimens 
of Gyraulus convexiusculus (Hutton) obtained in the Hamun-i- 
Helmand, Seistan. ‘Iwo molluscs, out of forty-three which were 
examined, contained examples of the parasite. 
ADDENDUM. 
With Dr. Kemp’s permission I add here three figures of 
the parasite of Schizothorax zarudnyi referred to by Mr. S. L. Hora 
TexT-F1G, 2.—Parasite from Schizothorax zarudnyt. 
and myself on p. 173 of this volume. The figures have been 
placed at my disposal by Major R. B. Seymour Sewell, I.M.S. 
and represent three views of the animal as seen as a solid object (A) 
and mounted in glycerine (B & C) after extraction from the 
cysts in the muscles of the fish. Their magnification is not stated, 
but it is at least 12 as reproduced. ‘The structure of the organism is 
so enigmatic that none of us are able even to suggest its taxonomic 
position. - The preservative had apparently failed to penetrate the 
