1919] Hine: Genus Erax 141 



giving more or less the appearance of a faded condition to the tibiae 

 and even to the other parts of the legs. Legs with much pale yellow 

 hair and black and some pale bristles. Male. First and second 

 abdominal segments gray pollinose with rather sparse pale hairs, 

 segments three, four and five with prominent white pile parted at the 

 middle and directed outward; segment six similar, but pile much less 

 prominent; segment seven silvery pollinose with short and scattered 

 white hairs. Hypopygium, from dorsal view, rather narrow, sides 

 nearly parallel to apical third then gradually widened; from side view, 

 rather long of nearly the same width throughout and with a prominent 

 extension apically. See Figures 1 and 33. Female, abdomen nearly 

 uniformly gray pollinose, oviduct shining black, somewhat longer 

 than abdominal segments five, six and seven. 



Several specimens of both sexes from Montana and 

 Wyoming. 



It is quite nearly related to rapax, as Osten Sacken stated 

 when he described the latter. The smaller size and the fact 

 that the entire third abdominal segment is silvery seem to 

 distinguish stramineus. A quantity of material, including 

 the two species, is at hand from the territory extending from 

 Montana to Guadalajara, Mexico, and I find it difficult to 

 make a satisfactory separation from all localities, but this is 

 easy to do with specimens from the northern and southern 

 limits of the area indicated. 



Erax dubius Williston. 



There is some doubt of the status of this species, for Williston 

 gave the name in a key in Volume 12, Transaction of the 

 American Entomological Society, page 64, but did not give 

 a description in full. It is reasonably sure, however, that his 

 short diagnosis of Erax n. sp., on page 68 of the same paper, 

 refers to dubius. A distinct effort has been made to properly 

 identify the species. By correspondence with C. P. Alexander, 

 of the University of Kansas, I find that the specimen which 

 Williston mentions from Washington has been lost, but a 

 specimen from Arizona, very likely that one referred to in the 

 diagnosis, is labelled as the type in the museum at Lawrence. 

 A study of this proves it to be very near stramineus, but with 

 black femora and red tibiae and tarsi. The color of the body 

 is exactly that of stramineus and the form of the hypopygium 

 is the same. Williston described stramineus as having entirely 

 black legs, but the fact is that in a long series of specimens 



