CULICIDAE — CHIRONOMIDAE. 5 



ence, surprising as it is, does not seem to me to have systematic 

 importance enough to require a separation of the Phoridce from 

 the remaining Brachycera, and the less so as similar deviations, 

 though not nearly of so striking a nature, also occur in other fami- 

 lies. I mention, as an instance, the remarkably stunted second joint 

 of the antennas in the genus Haltericerus Rond. among the Doli- 

 chopidee. 



I. NEMO CERA. 

 Fam. I. CULICIDAE. 



Charact. — Ocelli none. Thorax without transverse suture. Costal vein 

 continued round the margin of the wing, fringed with scales ; veins 

 in their last subdivisions more than six in number. 



This family, rich in species, comprises only a small number of 

 genera. As such, the old well-known genera Culex, AiiDES, 

 Anopheles, and Corethra are to be named first, being those 

 among which Meigen has distributed the European species. To 

 them may be added the genera Megarhina, Psorophora, and Sa- 

 bethes, separated from Culex by Rob. Desvoidy, the two last being 

 scarcely tenable, whereas Megarhina is acknowledged as holding- 

 good. The genus Mochlonyx, established by me, is very near to 

 Corethra, differing, however, by the abbreviation of the first tarsal 

 joint. 



Species of the genera Culex and Anopheles occur over all 

 parts of X. A., whereas Megarhina and Psorophora are only 

 represented by single species belonging, as it seems, more to the 

 South, as is also Corethra by C. punctipennis Say. 



Fam. II. CHIROXOMIDAE. 



Charact. — Ocelli none. Thorax without transverse suture. Wings with- 

 out vein along the posterior margin ; costal vein ending near the 

 tip of the wing. 



This family is not much richer in genera than that of the Culicidce, 

 but far more so in species. It contains the old and well-established 

 genera Chironomus, Tanypus, and Ceratopogon, to which have 

 been added the genera Hyd-rob^nus Fries (= Corynocerus Ruthe), 



