12 
Psyche 
[March 
NOTES ON THE GENUS PROCTACANTHUS WITH THE 
DESCRIPTIONS OF TWO NEW SPECIES (DIPTERA: 
ASILIDAE) 
By Stanley W. Bromley. 
Prodacanthus is a genus of large robber flies, the majority 
of species of which are found in the New World. Practically all 
the species with which I am familiar inhabit dry fields or pas- 
tures, several being restricted to dry sandy plains. 
In 1923, I published a short article (Psyche, Vol. XXX, No. 
2, April, 1923, pp. 41-45.) dealing with the food habits of two 
species ( Prodacanthus rufus Willist. and P. brevipennis Wied.) 
occurring in the latter situations. I did not mention in the 
article that the species concerned were identified by myself by 
comparison with specimens determined by Mr. C. W. Johnson. 
Since the publication of this paper, I discovered that the 
specimens, determined as P. rufus Willist. would not fit the des- 
cription of this species as given by Hine (Annals Ent. Soc. Am. 
Vol. IV, pp. 153-172. 1911) but rather would run to the next 
species given as rufiventris Macq. The principal differences be- 
tween the two are cited by Hine as being the enlarged hypopy- 
gium and uniform red thorax in rufus , against the darker thorax 
with nearly black stripes and spots and the narrow hypopygium 
(narrower than the last segment) of rufiventris . 
Unfortunately, no mention is made of the latter character 
in Williston’s original description which fits, as far as it goes, 
the specimens which I had noted as rufus. 
In August 1925, I collected a species of Prodacanthus in 
the sandy areas along the Rio Grande near Albuquerque, N. 
Mexico. These specimens agreed with Hine’s description of 
rufus, and differed as noted from the New England specimens. 
Since then I have examined a number of collections from states 
on the Atlantic Coast from South Carolina north to Maine and 
have found plenty of specimens of what Hine describes as ru- 
fiventris, but none from this region of what he describes as rufus. 
Now Williston’s specimens were from Masaschusetts and North 
