112 Annals Entomological Society of America [Vol. XII, 



Female. Total length 31 millimeters with tip of ovipositor broken 

 off, probably 34 or 35 millimeters when complete, colored like the male, 

 but segments six and seven not silvery, stump of the anterior branch of 

 the third vein much longer than in the other sex. 



Type: Male and allotype, from Round Mountain, Texas, 

 deposited in the museum of the -Philadelphia Academy of 

 Natural Sciences. 



This is the largest Erax I have ever seen. It suggests bicolor 

 but aside from its being much larger the costa is more strongly 

 dilated, the disc of the scutellum has black hair instead of 

 white, and the male genitalia are different. 



Erax zonatus n. sp. 



Male. Total length 16 millimeters. Vestiture of the head largely 

 white, several black bristles in the mystax and numerous black hairs 

 on the palpi. Tibiae red except at extreme apex, tarsi largely red, but 

 somewhat darker than the tibise and furnished with numerous black 

 bristles, femora black. Thorax quite unifonnly yellowish gray pollinose 

 with the usual marking very obscurely shown. Wings very slightly 

 tinged with yellowish, nearly hyaline, costa just a little dilated, branching 

 of the third vein plainly beyond the base of second posterior cell, stump 

 slightly longer than the basal section. Abdomen with four black bands 

 as follows: One on the middl^ of the second segment and one on each 

 anterior margin of segments three, four and five. These black bands 

 all are wider than the gray bands following them. Segments six and 

 seven silvery. Hypopygium red, prominent ventrally, more so in 

 appearance because of a .ventral tuft of chestnut brown hairs. 



Female. Total length 18 millimeters. Colored like the male except 

 the sixth abdominal segment is banded with black like five, and seven 

 is black with a very narrow gra}^ posterior margin, ovipositor black, 

 about as long as abdominal segments five, six and seven. 



Type: Male and allotype from Southern Arizona, F. H. 

 Snow, August, 1902. Collection of the author. Ten other spec- 

 imens, some of them from the collection of the Academy of 

 Natural Sciences, Philadelphia. Habitat, San Antonio Canyon, 

 California, Southern Arizona and Alamogordo, New Mexico. 



Easily known from all species of its group by the zonate 

 appearance of the abdomen, and the prominent array of 

 ventral hairs on the hypopygium, most conspicuous basally. 



Erax armatus Hine. 



There are three species of Erax with the hind tibiae modified in the 

 male. All are larger than the average. In the male the furcation of 

 the third vein is beyond the base of the second posterior cell, while in 

 the females it is usually about opposite the base of that cell. Stump 



