XIX. CONTRIBUTIONS TO THE ANATOMY OF 

 AQUATIC DIPTERA. 



1. LARVAL AND PUPAL STAGES OF AN INDIAN 

 CHAOBORUS AND DIXA. 



By Baini Prashad, D.Sc, Superintendent of Fisheries, Bengal Fisheries 

 Laboratory, Indian Museum, Calcutta. {Comrnunicated by permission 

 of the Director of Fisheries, Bengal.) 



(With Plate XIX.) 



In a previous communication ^ I described the anatomy of an Indian 

 Chironomid larva of the genus Polyjjedilum. The present paper 

 deals with the larval and pupal stages of two other Nematocera— 

 Chaoborus and Dixa. It is hoped that it may be followed by others on 

 various aquatic Diptera, our knowledge of the Indian forms being in a 

 very unsatisfactory condition. Most of the material for the present 

 investigation was put at my disposal by the Director of the Zoological 

 Survey of India ; some I had collected myself. 



The larvae and pupae of the Corethrid Chaoborus were collected 

 by Dr. Annandale in the Limnociiida pool in the river Yenna, at Medha 

 in the Satara district, Bombay Presidency, during the first week of 

 March, 1918 ; the material was well preserved, and both larvae and 

 pupae were found in abundance. Besides this I had a large number of 

 larvae collected in the third week of April, 1912, at the same place 

 by Dr. F. H. Gravely. No pupae were obtained on this occasion, 

 though larvae were abundant. I also had for comparison a single 

 specimen collected by myself in a shady pool in the Lawrence 

 Gardens, Lahore, in the month of November, 1916 ; observations were 

 made on this living larva whilst it was kept in a small aquarium in the 

 Zoological Laboratory of the Government College, Lahore, for a period 

 of over two months ; the larva even after this long period did not pupate 

 and was preserved in formalin. A few remarks about the name of the 

 fly to which the larvae and pupae belong would not be out of place 

 here. Giles^ in 1910 described the fly as Corethra asiatiea as a new 

 species from Shahjahanpur, and it was referred to as such by Theobald.^ 

 Edwards, however, has recently * shown that the form is specifically 

 identical with the one described by Schiner in 1868 as Corethra mani- 

 lensis {Reise Novara, Diptera, p. 30). Further, the species does not belong 

 to the genus Corethra as now restricted, but is a Chaoborus. The name 

 of the fly must, therefore, be Chaoborus manilensis (Schiner). 



The larvae and pupae of Dixa were collected by Major S. R. Christo- 

 phers, I.M.S., from the hill streams at Kasauli in February. 1914. A 

 large number of flies was reared by him, and the whole collection of 



1 Rec. Ind. Mus., XIV, pp. 71-74, pi. xxiii (1918). 



2 Journ. Bombay Nat. Hiat. Soc, XIII, p. (510 (1910). 

 * Genera Insectoruui, Diptera, p. 43 (1905). 



4 Bull. Ent. lies., IV, p. 242 (1U13-14). 



