122 Annals Entomological Society of America [Vol. XII, 



but nearly all red in some specimens, although all I have seen have at 

 least a trace of black on the front side of each; tibiae red, darker apically, 

 tarsi dark red with black bristles. Wings yellowish, slightly more 

 intense toward apex, male costa slightly dilated. Abdomen dark, 

 gray pollinose on venter and sides. Male with segments six and seven 

 silvery, genitalia shining black with an extension apically attached below 

 and directed upward. See Figure 28. 



Female colored like the male, except femora are more extensively 

 red than in the other sex in some of the specimens studied. 



The females taken in the same locality as the males, as well 

 as other females before me, agree with Bellardi's description of 

 marginatiis. He described affinis from a male and marginatus 

 from a female. It appears that they are sexes of the same 

 species. 



Specimens from Mexico and from Bonda, Columbia, S. A. 



Erax kansensis n. sp. 



Total length 17 millimeters. Mystax largely pale straw yellow, 

 but with some black bristles intermixed, palpi clothed with black hair, 

 beard nearly white, though with a tinge of straw color. Thorax above 

 with black and white pile and some black bristles; wings hyaline, a 

 tinge of brownish in the apical part of the marginal cell, costa not 

 dilated, anterior branch of the third vein with only an indication of a 

 stump; femora, apexes of tibiae and entire tarsi black, basal three-fourths 

 or more of tibia bright yellow; abdomen dark in ground color, largely 

 thinly gray pollinose, seventh segment just slightly silvery. Male 

 genitalia narrow; not long, narrowed suddenly and bearing at the 

 tip an angular extension. See Figure 19. 



Female colored like the male, genitalia rather wide and somewhat 

 longer than abdominal segments five, six and seven. 



Type: Male and allotype, from Clark County, Kansas, 

 elevation 1962 feet. F. H. Snow. In the author's collection. 

 Easily identified by the male genitalia. Most closely related 

 to apicalis. 



Erax aurimystaceus n. sp. 



Length of male 13 millimeters. Mystax rather large, golden yellow, 

 beard paler yellow. Thoracic dorsum with numerous rather long black 

 hairs and some pale yellowish hairs intemiixed on the posterior part 

 where they are distinctly longer than on anterior part. Scutellum with 

 numerous pale hairs on the disc and two black bristles apically. Wings 

 uniformly very pale yellowish hyaline, femora entirely deep black, 

 tibiae bright yellow with extreme apexes black, tarsi darker, but mostly 

 reddish, with numerous black bristles. Legs clothed with fine pale 

 hairs and black bristles. Abdomen yellowish gray pollinose, segments 

 two to five each with a large quadrate black spot above, segments six 



