April, 1911.] New Species of Diptera of the Genus Erax. 311 



Female abdomen Avith each segment white pollinose at sides 

 and apex, otherwise black above, ovipositor black, scarcely five 

 millimeters in length, equivalent to the last three abdominal 

 segments. 



Twenty specimens received from F. Grinnell, Jr., and taken in 

 Los Angeles County, California. A very distinct species on 

 account of the male hypopygium which appears as if inflated and 

 is nearly twice as wide as the seventh abdominal segment. 



Erax nemoralis n. sp. A dark colored species with yellowish 

 mystax and fumose wings. Femora, tarsi and apices of the 

 tibiae black, bases of tibiae reddish-brown. Length, male about 

 25 millimeters, female to the tip of the ovipositer, 2-4 to 27 

 millimeters. 



Face and front covered with yellowish dust, mystax and beard 

 pale yellow, occipito-orbital and ocellar bristles black, as are 

 most all of the hairs and bristles of the front, palpi black, fur- 

 nished with many black hairs which often are intermixed with 

 pale yellow ones. Prothorax mostly clothed with pale hairs, 

 remainder of thorax with many black hairs and bristles, but 

 these often are reduced by the presence of greater or less numbers 

 of pale ones; middorsal stripe dark and well marked, abbreviated 

 behind and divided anteriorly, on either side the markings are in 

 the form of ill-defined spots caused by the difference in intensity 

 of the n.ist -colored dust which gives the thorax its peculiar color; 

 legs black except the bases of the tibiae which are reddish-brown, 

 clothed with black bristles and pale hairs of different lengths, the 

 shorter ones recumbent, some of the segments inwardly, more 

 especially the metatarsi and front tibia, clothed with golden 

 recmnbent pile. 



In the male abdominal segments one, two and base of three 

 dark, largely clothed with black hair, apex of three and all of four, 

 with the exception of a small black triangle on each anteriorly, 

 white with long white hair parted at the middle and directed out- 

 ward, five and six silver white with very short hair, remainder of 

 the abdomen black, with black hair, however, in some specimens 

 part of seven is whitish and there may be a few pale hairs on the 

 hypop3^gium. 



In the female the segments of the abdomen are gray on the 

 sides and hind margin, otherwise black above but the latter color 

 is not well defined, especially if viewed with a lense; ovipositor 

 about six millimeters in length, equivalent to the last fotir 

 abdominal segments. 



Several specimens of both sexes procured in a brushy woodland 

 at New Roads, Louisiana, July 15, 1905. The specimens were 

 captured while resting near or on the ground. It is a predaceous 

 insect of possible value on account of its size. 



