210 DOLICHOPID^E. 



fringe. Abdomen of the male compressed, the second and third seg- 

 ments yellow, except the hind margin ; in the female only the second 

 segment yellow, forming a band slightly interrupted. Fore coxae, the 

 femora, tibiae, and anterior metatarsi yellow, hind femora and tibiae 

 blackish at the tip. 



Very rare. In Mr. Haliday's collection. (S.) 



Genus XL PORPHYROPS. 



PORPHYROPS p., Mg. zw. iv. (1824). Medeterus p., Mq. ; Mg. Ar- 

 yyra p., Mg. Lolichopus p., Fb. s. a. ; Dml. ; Fin. ; Ztt. Musca 

 p., Fb. 



Antenna articulo tertio apice attenuato ; arista dorsali. Alee vena sub- 

 costali costce trientem vix super ante, transversa a margine alee distante. 

 Abdomen subcylindricum aut compressiusculum, segmento secundo primi 

 longitudinem superante, hypopygio maris brevi, in apice abdominis plus 

 minusve immerso. 



Antenna with the first joint naked, the third joint attenuated to the 

 tip, usually broader than long ; the arista placed on the upper edge and 

 seldom far from the base of it. Eyes distant on the front ; face narrow 

 in the male, the eyes even meeting in some. Proboscis short, obtuse. 

 Wings with the subcostal vein not continued much beyond one-third of the 

 costal margin, ending, therefore, more nearly opposite the middle, than the 

 tip of the discal areolet; discal transverse vein distant from the hind 

 margin by more than its own length, often by twice that. Abdomen some- 

 what cylindrical, or compressed, in the male at least ; with the hypopy- 

 gium short, more or less imbedded in the tip of the abdomen, varying much 

 in size ; the second segment of the abdomen longer than the first. The 

 spines of the posterior tibias usually few, often very slight, and the fore 

 pair usually almost unarmed. 



This genus is retained in order to receive the species with the 

 third joint of the antennae somewhat angular at the tip, and the 

 arista dorsal, which have not the hypopygium so much developed 

 as in DolichopuSj while they are excluded from Hydrophorus by 

 the distance of the transverse vein from the margin, from Camp- 

 sicnemus by the form of the abdomen and the proportions of the 

 segments, and from Argyra as having neither the subcostal vein 

 of the wings elongated, nor the first joint of the antennas pubes- 

 cent. They have, therefore, not many positive distinctive cha- 

 racters in common. P. aidicus would find a more natural place in 

 the group with which the genus Rhaphium ends, while P.flaviven- 

 tris has some likeness to a Sylistroma. 



