Vik I, No.3. | The Hydra of the Calcutta Tanks. (es 
ceases at the commencement of the hot weather.) Budding oc- 
curs simultaneously. I have not seen more than two buds on one 
adult at the same time, and one is commoner; nor have I seen an 
attached bud budding. The food consists chiefly of small Crustacea 
and worms. Large Daphniids on coming in contact with the ne- 
matocysts are temporarily paralysed but break loose through their 
own weight and recover movement after a few minutes. Adult 
Polyps show little inclination to leave a situation in which they 
have settled, and buds rarely move far from their parents ; conse- 
quently, large numbers of individuals may often be found within a 
small radius in the tanks, though there may be none on the sur- 
rounding plants. Im an aquarium they desert the water-plants 
and take up a position on the side of the glass farthest from the 
light. If starved they become extremely pale and attenuated 
within a day or two, their colour disappearing very much more 
rapidly than it does when they are well fed but kept in a bright 
light. They do not seem to be able to endure a change of tem- 
perature such as that brought about by the sun shining directly 
on the surface of the water in a large glass jar. 
So far as I am aware, the genus Hydra has not previously 
been recorded from British India, but a species (H. fusca ?)? is re- 
ported from Tonkin. The late Professor J. Wood-Mason, as 
Major Alcock informs me, collected many specimens in Calcutta. 
I have myself seen a species (probably the same as the Calcutta one) 
in an aquarium in the Experimental Gardens at Penang. 
1 Since the beginning of the hot weather my captive specimens have disap- 
peared, and I have not been able to find any free in the tanks. April 12th 
1905. This remark still holds good. July 21st, 1905. 
2 Richard, Mem. Soc. zool. France, vii, p. 287. What may be the same: 
species is recorded from Turkestan (Daday, Zool. Jahrb. Syst., 1904. p. 480). 
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