AMERICAN DIPTERA. 187 



specimens a much richer appearance. The white pruinose 

 spots do not appear to cross the posterior borders of the 

 segments as Loew says, but are recognizable only on the pos- 

 terior lateral margins. There is one famale in Osten Sacken's 

 collection from Kansas labeled " eutrophus" which agrees with 

 the type specimens except that the thoracic dorsum is yellow- 

 ish-red with a trace of dark median line. 



Osten Sacken in his "Western Diptera," page 291, suggests 

 that rhadamanthus may prove the male of eutrophus, and 

 indeed this has seemed probable, inasmuch as hitherto they 

 have been represented in collections by males and females 

 respectively. But there are now at the National Museum two 

 males which are of the same size as the females of eutrophus, 

 and agree with the type material except that they have a 

 reddish thoracic dorsum. In this last respect they agree with 

 rhadamanthus, but their larger size and general appearance 

 make it easy to separate them. I am inclined to think that 

 eutrophus is distinct from rhadamanthus. This will be a ques- 

 tion for discussion until more collecting has been done. At 

 present rhadamanthus is represented only by three males at 

 the M. C. Z. Eutrophus is found, aside from the type material, 

 in small numbers in the collections of the National Museum, 

 the American Entomological Society, the University of Kan- 

 sas and that of Prof. C. W. Johnson. 



Ospriocerus niiiios. 



Osprioceriis minos Osten Sacken, West. Dipt., 291, 1877. 

 r^.— -Length 17-18 mm. — Altogether black; wings blackish. The 

 face is slightly grayish pruinose; the abdomen is more cylindrical, less 

 flattened than in the male of abdominalis, and the last antennal seg- 

 ment seems a trifle longer. In other respects this species is like 

 abdominalis. 



Type. — M. C. Z. A single male specimen. 



Habitat. — Golden City (July 3, A. S. Packard), Col. 



There is nothing to add to the above description. I have 

 referred two females from Colorado belonging to the American 

 Entomological Society to this species. 



Ospriocerus rhadaniautlms. 



Ospriocerus rhadamanthtis Loew, Cent., VII, 52, 1866. 

 Ospriocerus rhadamanthus Osten Sacken, West. Dipt., 1877, 290. 



TRANS. AM. ENT. SOC, XXXV. MAY, 1909. 



