130 Annals Entomological Society of America [Vol. XII, 



A male specimen from San Domingo. This species agrees 

 exceedingly well with Macquart's description of fulvibarbis 

 and comes from the type locality. The row of six or more 

 bristles on outside of hind femur easily suggests the species. 



Erax haloesus Walker. 



Total length 18 millimeters. Mystax white with numerous heavy 

 black bristles, beard white, scutellum with white hairs on its disc and 

 about four rather slender black bristles on its margin; tibiae bright 

 reddish yellow, except distally, tips of tibiae and tarsi black, although 

 the latter may be partly dark reddish brown, costa not thickened, wings 

 dilute yellowish hyaline. See Figure 30. Hypopygium elongate, 

 distinctly red at tip. 



A male specimen from Jamaica furnished by C. W. Johnson 

 by whom it was identified. The hypopygium enables this species 

 to be determined readily. 



Erax nigrimystaceus Macquart. 



Total length 1 7 millimeters. Mystax largely black with pale yellow- 

 ish hairs intermixed, palpi with black hairs, beard straw yellow, thorax 

 dark, gray pollinose, bristles and hairs black, many black upright 

 hairs on the scutellum, wings distinctly yellowish, a little more intensely 

 so toward apex, costal border plainly, though not strikingly, dilated, 

 stump of the anterior branch of the third vein very short, not half 

 the length of the connecting vein; entire femora, apexes of tibiae and 

 tarsi clear black, basal three-fourths or more of tibiae brown. Abdomen 

 dark, partially gray pollinose, segments six and seven silvery. 

 Hypopygium black, not tumid, gradually widened from the base to 

 beyond middle then slightly narrowed and truncate at apex with two 

 minute emarginations, one dorsal and the other ventral. See Figure 31. 



Male from Dominica, West Indies, November, 1903. 

 Furnished by Chas. W. Johnson. 



The carinatus Group. 



In Western United States and extending into Mexico and Central 

 America' there are several species of the genus Erax that are distinct 

 from the others on account of the following characters : 



The dorsum of the mesothorax is more convex than usual, with a 

 distinct crest of erect hairs on the middle of the dorsum, beginning just 

 behind the head and extending back to beyond half the distance to the 

 scutellum. Branching of the third vein beyond the base of the second 

 posterior cell; stump rudimentary or altogether absent in the male, 

 present and somewhat variable in length in the female; costa in the 

 male always thickened and expanded but much more evident in some 



