380 INSSCTA, 



designated this last genus by the name of Ckrosomtjza. We will 

 unite these two genera in the single subgenus 



MosiLLUs, Lat. 



I have often found numbers of the M. arcuatus on tlie dust of old 

 walls*. 



Those species, in which the first cells of the posterior edge of the 

 wings are entirely open and longitudinal, composed, in the work of 

 Meigen, two other genera: 



HoMALURA, where the abdomen presents five segments, and Ac- 

 tor a, where it exhibits six. The head is still more compressed than 

 in the preceding subgenera. The seta, according to him. is naked, 

 but I have seen it plumous in some specimensf. 



There, the attennse are almost contiguous ; the cells of the poste- 

 rior edge of the wings are always open. 



Those Gymnomyzides in which the attennse are very short, and 

 inserted, as in the last subgenus, under a sort of arch and near the 

 middle of the face, form the genus Gymnomyza of Fallen J. Those 

 in which these organs are inserted higher up, without any distinct 

 appearance of an arch at their origin, and that terminate in an elon- 

 gated palette, compose the genus Loxch.ea of Fallen and Meigen. 

 According to the latter the front is narrower in the males than in the 

 females, and we see by their character that these Insects are con- 

 nected in some respects with various species of Anthomyzae§. The 

 antennae of the Celyphi and Lauxaniae are also inserted higher than 

 in the other GymnomyzEe. 



Our second section of the Muscides, which will form our ninth 

 and last sub-tribe or general division, that of the Hypocera, com- 

 prises but a single subgenus, very distinct from the preceding ones 

 in several characters. The palpi are always exterior ; the antennae 

 inserted near the oral cavity are very short, and terminated by a 

 thick and almost globular joint, with a very long seta. The wings, 

 whose edge is densely ciliate superiorly, present near the base a stout 

 oblique nervure, whicli extends to the margin where this stigma 

 is placed in the Hymenoptera, and from this nervure proceed three 

 others which run almost parallel with each other, in a longitudinal 

 direction ; hence the origin of the name Trineura, given to this sub- 

 genus by M. Meigen. The body is arcuated, the legs stout and 

 spinous, and their thighs large and compressed, the posterior ones 

 particularly. These Insects are extremely vivacious, and form in 

 our " Genera" the genus 



Phora, Lat. — Trineura, Meig. 



In the Diptera of which we have hitherto spoken, we have found a 

 sucker received into^the superior canal of a tubular sheath, more or 

 less membranous, geniculate at base, most frequently terminated by 



* See Lat, Gen. Crust, et Insect, IV, 357; Meig., et Fallen. 



t See Meigen. 



X Fallen, Dipt. 



§ Fall, and Meigen. 



