CEKATOPOGON. 207 



of the body. When disturbed, it moves its head and thorax quickly 

 from side to side. The upper side of the pupa-case is slit open 

 when the fly emerges. 



The larva of C. lateralis inhabits manure, and has no clavate 

 setee, but is furnished with two pediform appendages on the pro- 

 thorax and on the anal extremity ; the pupa has also eight long 

 filiform appendages on the back of the thorax. The sexes generally 

 differ slightly in the disposition of the wing-veins, and these dif- 

 ferences will be most clearly seen by referring to the excellent figures 

 in Winnertz's elaborate monograph on this genus. 



These flies are generally called Midges, and the females of some 

 of them are blood-suckers, and are very annoying when they occur 

 in great numbers. The species whose femora are armed with spines 

 make a prey of other small insects, which they pierce with their 

 sharp proboscis. The larvae live in water, or in the earth, or under 

 the bark of trees, and the transformation of C. bipunctatus has 

 been frequently observed. 



The following divisions are copied from Winnertz's mono- 

 graph : 



A. Antennae with the five last joints elongated. 



A. Wings with two cubital areolets, or (the first being confluent) with 

 one, distant from the prsebrachial. 



a. Wings wholly or partly hairy, quite bare in the males of some 

 species. Femora simple, unarmed. 



b. Ungues with hairy onychia. Ungues of both sexes of equal 

 length. 



c. First tarsal joint shorter than the second, or both of equal 

 length. Fordpomyia, Megerle. Labidomyia, Steph. 

 d. Subcostal vein united to the costal in the middle of the 



fore border, or before it. Species 1-4. 

 d d. Subcostal vein united to the costal between the middle 

 of the fore border and the tip of the wing. Species 5-7. 

 c c. First tarsal joint longer than the second. 



d. Subcostal vein united to the costal in the middle of the 



fore border or before it. Species 8-14. 

 d d. Subcostal vein united to the costal between the middle 

 of the fore border and the tip of the wing. Species 15-27. 

 b b, Ungues with bristly hairs instead of onychia. Ungues of both 

 sexes of equal length. 

 c. First tarsal joint longer than the second. 



d. Subcostal vein united to the costal in the middle of the 



fore border or before it. Species 28. 

 d d. Subcostal vein united to the costal between the middle 

 of the fore border and the tip of the wing. Culicoides, 

 Latr. Species 29-45. 



