360 



to caption 15. Including suhnigripes {=mgripcs Schiner ncc Meigen) 

 there are four species occurring in North America that fall here ; they 

 may be separated thus : 



a. Squamae gray, fringes brown suhnigripes Malloch. 



— • Squamae and fringes Avhitish aa 



aa. Cross veins separated by about the length of outer eross-vein 



aprilina, n. sp. 



— Cross veins separated by about twice the length of outer cross- 



vein aaa 



aaa. Arista almost bare ; occiput not projecting on upper half 



ahhrcviaia Malloch. 



— Arista distinctly pubescent ; occiput projecting on upper half 



kincaidi Malloch. 



CHLOROPID.E 

 Gaurax Loew 



I recently described two new species of the genus Caurax and pub- 

 lished a synoptic key to the North American species*. Since sending 

 that paper in for publication I have found three species which are evi- 

 dently undescribed, and in presenting descriptions of these I feel that 

 it becomes necessary to publish an enlarged synopsis of the species so 

 that students may the more readily recognize the new forms. 



I have not found any of the early stages of the species; most of the 

 imagines occurring on tree-trunks and limbs. Several examples of 

 dorsaUs Loew were taken on windows of the basement in the Natural 

 History Building of the University of Illinois. 



In the case of the specimens of montanus Coquillett which I took 

 here the apices of the hind femora are slightly brownish, a character 

 possessed by the type also, though omitted in the original description. 



Key to Species. 



1. Wings not entirely hyaline, either with a black spot at apex of sec- 



ond vein, or with a distinct dark mark or inf uscation on disc .... 2 



— Wings entirely hyaline 7 



2. Wings with a small black spot at apex of second vein (Toronto, Can.) 



pseudostigma Johnson. 



— Wings with a much greater portion blackened 3 



3. Thorax and scutellum entirely yellow ; a large black mark occupying 



the area of the wings from middle of second vein between costa 

 and third vein and a small portion of the apex of the cell posterior 

 to third (111.) flavididus, n. sp. 



*Proe. Ent. Soc. Wash., Vol. 17, 1915, p. 159. 



