Anopheles nigerrimus. 



veins, especially opposite the anterior and posterior branches of the 

 fifth long vein. 



Characters of the larva. The larva of A. nigerrimus resembles 

 that of A. barbirostris very closely. The median frontal hairs 

 are unbranched but may be bifurcated at their extremities. The 

 external frontal hairs are very much branched, so that they form 

 distinct " cocades " in front of the whorl organs. The antennae 

 possess a large branching hair on their inner side as in the larva of 

 A. barbirostris. Palmate hairs are borne by the second to the 

 fifth abdominal segments. 



Habitat and observations. This is a fairly common species in 

 the outskirts of Calcutta and in other places in the plains of 

 Bengal. It also occurs in Travancore and in the Madras and 



o 



Bombay Presidencies. 



It has been shown that the embryos of " Filaria Bancroft! " 

 can develop in this species as well as in A. rosti. Its larvae are 

 usually found in deep shady pools, containing grass and water weed, 

 at some distance from habitations, and the adults are seldom met 

 with in houses. 



A large number of species closely resembling ,4. nigerrimus 

 have been described, but it is very probable that the majority are 

 only varieties (or perhaps representatives of local races or sub- 

 species) of a single type. The following forms are described as 

 distinct species by Mr. Theobald : vanus, sinensis, rninutus, 

 indiensis, fiseudopictus, and alboannulatus. A. vanus is recorded as 

 occurring in Travancore, A. minutus in Lahore, and A. indiensis 

 in Madras. According to Colonel Giles, who has apparently examin- 

 ed the single specimen of A minutus in the British Museum, 

 its only difference from other members of the "sinensis group" 

 is the fact that the wing spots are white instead of yellow a 

 distinction which, of course, is no value. Between A. alboannulatus 

 and A. vanus, Colonel Giles cannot detect any difference ; and A. 

 indiensis, differs from vanus only in a detail of wing venation 

 a character which has been shown to be very variable. 



[8 



