94 Records of the Indian Museum. [Vor. VII, 
commencement of the survey, the Museum did not possess a collec- 
tion of properly named mosquito larvae on which he could have 
based his identifications. Such a collection has now been formed, 
both of the common species obtained during the survey, and of some 
of those found in Calcutta tanks; and I should like to take this 
opportunity of thanking Major Christophers, I.M.S., and Capt. 
Davys, I.M.S., for the assistance they have given me by sending 
isolated larval and pupal skins, together with the adults which 
emerged from them, of several species not common in Calcutta. 
But the absence of Mr. Paiva on medical certificate, an absence 
which will certainly be of long duration and from which it is very 
doubtful whether it will ever be safe for him to return, has rendered 
it impossible for the Museum to undertake, as had been hoped might 
be made possible, a second and more thorough survey on the lines 
indicated above. And it isin the hope that the experience and 
unavoidably imperfect results of what has already been done may 
be of use to others that the present paper has been compiled.—F. H. 
GRAVELY, Asst. Supdt., Indian Museum. | 
Karly in October 1909, the Calcutta Corporation commenced the 
destruction of mosquito larvae in that part of the town locally known 
as the “‘ Fringe Area,”’ and asit wasimportant to know what species 
abounded in that area, living specimens of larvae were daily sent to 
the Indian Museum from every spot which was visited, together 
with the precise locality and breeding ground of these larvae. 
Larvae were received with considerable regularity but for two 
interruptions which were occasioned by the Durga Puja and Christ- 
mas vacations. The larvae were successfully reared in the Museum, 
and the mosquitoes that emerged from each batch were carefully 
pinned and labelled. After a large number had been collected, 
I identified them to the best of my ability. 
The Calcutta Corporation stopped the supply of mosquito 
larvae on the 26th February rg1o, without previously informing 
the Museum authorities that the work was not to be carried on 
any longer by them. As it was the intention of the authorities of 
the Museum to carry on the breeding of mosquito larvae for a com- 
plete year, arrangements had to be made to secure men to collect 
larvae during the remaining period, 7.e., till the first week of Octo- 
ber 1910. It was an extremely difficult task to secure really re- 
liable men for the work and this caused an interruption of a little 
more than three weeks. On the 22nd March ro1o, the work of col- 
lecting larvae commenced again, and after several changes of collec- 
tors, two men were finally selected for the work. In a short time 
the daily supply of larvae became enormous and consequently very 
large numbers of mosquitoes emerged daily. These could not all 
be pinned, so they were killed and put into separate pill-boxes 
and after all the mosquitoes had been thus duly arranged, I 
counted and identified them and made the necessary entries in a 
rough register. Thus did the work continue till the beginning of 
October IgIt. 
