NOLES, ON LARVAL, TREMA TO DHS Ho ROM 
S.#.1S TAN. 
By STaNLEY Kemp, Sc.D., Superintendent, Zoological 
Survey of India. 
The following notes on larval trematodes obtained during 
our visit to Seistan are admittedly very incomplete. In the field it 
was not possible to follow out the detailed anatomy of the various 
forms from living specimens and for this, it is to be feared, no 
subsequent work on preserved material can compensate. My 
notes are in the main based on preserved cercariae and on sections of 
infected livers. As a fixative Schaudinn’s solution, used hot, was 
employed ; while for staining haematoxylin followed by eosin gave 
the best results. 
In some instances cercariae were obtained in such small 
numbers that it has not been found possible to give any account of 
their anatomical characters. Of these one is a Xiphidiocercaria 
obtained in Melanotdes pyramis var. flavida at Saindak in the 
extreme west of Baluchistan and the other a furcocercous form 
with extremely long tail-flukes obtained in Gyvaulus euphraticus 
in the Hamun-i-Helmand, Of each of these only a single infection 
was discovered. The other three forms of cercariae are partially 
described below. One of them (Cercaria A) is a leptocercous form 
with rediae resembling those of Fusciola hepatica'. The other two 
(Cercaria B and C) are furcocercous forms ; one of these (B) 
bears a close resemblance to the larva of Schistosoma japonicum, 
but is distinguished by a number of characters. 
For the names of the molluscan hosts I am indebted to 
Dr. Annandale and Dr. Baini Prashad (see page 17 of this volume). 
Cercaria A (text-figs. I a—c). 
In well-preserved specimens the length of the body is from 290 
to 360 » (average 320 ») and the breadth 170 to 220 » (average 200 /). 
The tail is twice or more than twice as long as the body, being 
from 670 to 780 » in length (average 730 »). 
The body (figs. 1 a, 6) is oval in outline, distinctly exca- 
vate posteriorly at the insertion of the tail, and is relatively thick- 
walled. ‘The oral sucker is about 0°05 mm. in diameter. The 
acetabulum is approximately the same size and is situated slightly 
behind the middle of the body. ‘There is a small pharyngeal 
bulb situated on the undivided anterior portion of the gut close to 
1 Erroneously recorded as a monostome on-p. 22 of this volume. 
