52 Journal of the Asiatic Society of Bengal, [February, 1912. 
altogether unsuccessful in so doing. I must beg all those who 
are interested in natural history in India, and especially the 
zoological members of this Society, to give us their support 
d to take a practical interest in our work; for scien- 
tific work, like other branches of human activity, if it fails to 
attract the sympathy of educated men, is in danger of becom- 
ing either a valley of dry bones or a slough of despond. Even 
those who are completely ignorant of the technicalities of any 
science can help us greatly by sending us specimens of the 
animals that occur in ponds, rivers or lakes in different 
parts of the Indian Empire, and nobody need hesitate to send us 
such specimens because they are common. Most animals that 
are rare in museums are actually common somewhere, in a state 
of nature: they only appear to be rare because no one has 
taken the trouble to collect them in the particular locality 
in which they abound. In India and Burma, at any rate, it 
is probable that many of the most interesting aquatic species 
are still either altogether unknown or have as yet been imper- 
fectly studied. 
EXPLANATION OF PLATES. 
Plate I. 
Fie. 1. Tortoise (young of Kachuga dhongoka) with stato- 
ane of Plumatella testudinicola on its shell 
reduced). : 
Shells of the mollusc Vivipara bengalensis covered 
with colonies of Hislopia lacustris (dried speci- 
mens : nat. size). 
Fig. 
© 
Plate IT. 
Fic. 1. Specimens of the predaceous flat worm Temnocepala - 
sempert taken from freshwater crabs (Potamon 
mani) in Tenasserim (magnified) showing (A) 
rface. 
Fie. 2. Specimens of the Himalayan race of the sponge 
Ephydatia fluviatilis from the lakes of Kumaon 
educed). A—three Sponges growing on 
a stone; B—a sponge growing on a slender twig, 
and C—one growing on a forked twig. 
Plate IIT. 
g 8 i g on the roots of the floati ng wat 
Pistt ratt f { 1 - : 
