154 Records of the Indian Museum. [Vol. XV, 



larvae, pupae and flies presented to the Indian Museum, Calcutta. 

 The fly has been identified as Dixa montana, Brun., by Dr. Annandale 

 after comparison with the type-specimen. Mrs. Adie ^ has recorded 

 the finding of a large immber of larvae of a species of Dixa, in a pond 

 in the Lawrence Gardens, Lahore. On many occasions I tried in the 

 same place to obtain specimens but without success. 



LaEVA of ChAOJWRUS AIANILENSIS. 



The larvae at Medha were found in seven to twelve metres of water, 

 over a hard rock bottom covered with a thin layer of vegetable debris 

 and fine gravel, the water was muddy and opaque, and a slight trickle of 

 water was running in and out of the pool. The pond at Lahore is an 

 artificial one, overhung by large trees, and is about twenty feet across 

 and three to five feet deep ; it is full of dead leaves and the water is of a 

 muddy darkish colour ; it is every now and then replenished from a 

 canal. 



Observations made on the living larva at Lahore showed that its 

 habits are identical with those of the European species described by 

 Miall.^ It may be mentioned, however, that those described by him 

 {op. cit.) and by Wiesmann'^ as Corethra belong, like the form considered 

 in this paper, to the genus Chaoborus, Lichtenstein. The larva of the 

 genus Corethra, Meigen, is quite distinct, and is what is described by 

 Miall on page 121, as the larva of Monochlys. Very good figures of the 

 larvae of Chaoborus and Corethra are given by Howard, Dyar and Knab."* 



The full grown larvae are 7 — 8 mm. long. When living they are 

 transparent with the four air-sacs opaque and coppery. The alimentary 

 canal has a faint reddish tinge, especially in the middle region of the 

 abdomen. In older larvae the mass below the abdomen was tinged with 

 orange. The preserved specimens are milky white, the air-sacs brown- 

 ish black, the head round the eyes dark brown, elsewhere of the same 

 colour as the body ; the eyes themselves are of a dense black colour. 

 The division of the body into head, thorax and abdomen is very 

 distinct ; the neck is very small and in many specimens, owing to the 

 head being drawn underneath the thorax, cannot be seen. The head 

 is a very small structure, narrower than any of the body segments except 

 the last abdominal. Seen in a side view it is more or less triangular, 

 while in a dorsal view the basal part appears quadrangular with the eyes 

 at the anterior angles. The anterior part of the clypeus is of the shape 

 of a very much elongated and vertically flattened process, with the 

 extremity of which the antennae are articulated ; there being no pre- 

 antennal portion of the head. On the ventral side a little behind the 

 point of attachment of the antennae there is a large bunch of setae 

 hanging down from the vertical process of the clypeus mentioned above. 

 Behind the group of setae there are two elongated triangular flaps at- 

 tached to the same process ; these flaps are mobile and have their pos- 



1 Patton and Cragg, Eniomohxjy, p. 190 (1913). 



2 The Natural HiMory of Aquatic Insects, pp. 113-122 (1903). 



3 Zeits f. Wiss. ZooL, XVI, pp. 45-127, pis. iii-vii (ISGG). 



* The Mosquitoes oj' North and Central America and the West Indies, 1, j). l(iS, 

 pl. viii(iyi2). 



