begins at the angle in the prsefurca, almost immediately turning 

 outwards and running straight to the wing-tip. Anterior cross- 

 vein short, placed just at the bend of the 3rd vein. The 4th vein 

 forks just beyond the anterior cross-vein, the upper branch forking 

 again near its tip, the lower branch straight, simple. Basal side 

 of 3rd posterior cell rectangular; disced cell absent; posterior 

 cross-vein just beyond the base of the 3rd posterior cell. Four 

 posterior cells. The 6th vein nearly straight, the 7th vein absent, 

 or at least abortive, as there is a faint trace of a very short vein at 

 the extreme base of the hind angle of the wing. The venation is 

 remarkably consistent in all the Indian species. 



Range. Europe, Morocco, Asia Minor, Siberia, Himalayas, 

 China, North America and the West Indies. 



So long ago as 1714 Reaumur described the larva of Diva,* 

 and De G-eer t later on redescribed it, adding much further infor- 

 mation. 



Staeger has described the life-history (Reaumur's description 

 was of the larva only and not of the transformations) of a specier 

 from Denmark, D. nigra. J The transformations of several 

 European species are described by Meinert. 



The larva of Dixa has a habit of resting with its body in the form 

 of a siphon, that is to say, with its head and tail drawn up close 

 together, he intervening portion of its body curved into a loop, the 

 top of the loop being a little anterior to the middle of the body ; 

 in other words, the bend does not occur half-way between the ex- 

 tremities, but at the fifth and sixth segments behind the head. The 

 head has great flexibility, as it can be bent round parallel to the 

 rest of the body. It is hard, with a pair of branched antennae 

 and elongate, palp-like appendages about the mouth. There are 

 eleven segments to the body in addition to the head, the ultimate 

 segments bearing the caudal appendages, consisting of an elongate- 

 conical central piece which ends in three filaments, and two slender 

 flexible hairy side-pieces. The locomotive organs (pseudopods or 

 prolegs) are ventral, and not dorsal as has been stated by both 

 Reaumur and De Geer. They are armed with hooks, and are 

 placed on the fourth and fifth segments. On the eighth, ninth, 

 and tenth segments are bunches of setae which fulfil the office of 

 legs, and were mistaken for such by Reaumur. In some species 

 the dorsal surfaces of six of the segments (the fifth to the tenth 

 inclusive) bear oval shields fringed with setae. In other species 

 this character is absent. 



The larva grows to a length of less than half-an-inch. It is 

 found in pools overgrown with vegetation, resting on leaves just 

 above the surface of the water, and remains with its head and tail 

 close to the water's edge. If removed from the water it soon dies 



* Mem. de 1'Acacl. Boy. de Paris. 



t Mem. Hisfc. Ins. vi, p. 380(1776). 



t Naturh. Tidsskr. iv, p. 202 (1842). 



K. Danske Vid. Selsk. Skrift, iii, p. 452 (1886). 



S 



