January, 1901.] 



PSYCHE. 



149 



DIPTERA. 



BY D. W. COQUILLETT. 



Culex impiger Walker. This 

 species extends over nearly the whole of 

 North America, ranging as far south- 

 ward as Jamaica, W. Ind. 



Simulium venustum Say. Ranges 

 from Canada and British Columbia 

 southward to southern Florida and 

 Texas. 



Rhypholophus cockerellii, sp. 

 nov. 



Liglit yellow, the antennae and palpi ex- 

 cept basal joint, Ijrovvn (legs broken off in 

 the single specimen) ; joints of fiagellum of 

 antennae elong.ite oval, each bearing a whorl 

 of bristles; wings hyaline, stigma very faint, 

 discal cell opens into the third posterior, aux- 

 iliary crossvein slightly before middle of dis- 

 tance from base of third vein to apex of the 

 auxiliary, marginal crossvein near base of 

 anterior branch of second vein, seventh vein 

 diverging from the sixth on its basal three- 

 fourths, then extending parallel with it ; 

 length, 4 mm. 



A female specimen. Type No. 5317, 

 U. S. Nat. Museum. 



Limnophila costata, sp. nov. 



Head black, densely gray pruinose, first 

 two joints of antennae black, the remainder 

 brownish, the sutures yellow; flagellar joints _ 

 elongate oval, towards apex of antennae In- 

 coming almost cylindrical, each much long- 

 er than broad and bearing a whorl of bristles ; 

 mouth parts black; body black, subopaque, 

 thinly grayish pruinose, a -spot above each 

 front coxa and the genitalia, yellowish ; coxae 

 and base of femora yellow, remainder of femo- 

 ra brown ; tibiae and base of tarsi yellow, 

 apices of tarsi brown ; halteres yellow, the 

 knobs brown ; wings liyaline, the apices 

 and hind margins pale gray, costal cell 



brown, stigma dark brown ; auxiliary vein 

 curving toward the first and ending in it 

 noticeably before base of first submarginal 

 cell, a crossvein situated considerably be- 

 fore the apex of the auxiliary vein connects 

 it with the costa; marginal crossvein close 

 to apex of first vein and near middle of upper 

 branch of the second, petiole of first submar- 

 ginal cell shorter than the great crossvein, 

 the latter near middle of discal cell, five pos- 

 terior cells, the second subequal in length to 

 its petiole, no supernumerary crossveins : 

 length, 9 mm. 



A female specimen. Type No. 5318, 

 U. S. Nat. Museum. 



Tabanus rhombicus O. S. This 

 species was originally described from 

 the mountains of Colorado. 



Cyrtopogon callipedilus Loew. 

 Hitherto recorded from northern Cali- 

 fornia and Wyoming. 



Empis poplitea Loew. Originally 

 described from Alaska, and also occur- 

 ring in Colorado. 



Syrphus arcuatus Fallen. A Euro- 

 pean species which also occurs over the 

 greater part of North America north of 

 Virginia and Mexico. 



Syrphus creper Snow. Originally 

 described (rom the mountains of Colo- 

 rado and New Mexico. 



Chrysotoxum derivatum Walker. 

 Extends from Kansas and New Mexico 

 westward to the ocean and northward 

 into British America. 



Volucella facialis Williston. Hith- 

 erto known to occur in Colorado, Wash- 

 ington and Alaska. 



Arctophila flagrans Osten Sacken. 

 Occurs in New Mexico, Colorado and 

 Alaska. 



