42 KANSAS UNIVERSt'lV (^)UARTERLV. 



Female. Front narrow above, the eyes separated by the ocellar 

 tubercle; deep black, silvery white near the antenna? and with a white 

 spot near the middle. Abdomen less slender. 



Three specimens, Colorado, Estes Park, Prof. F. H. Snow. 



This genus is related to Systropus, yet is very distinct. Schiner 

 ■did not seem to grasp the true differences, though he insisted there 

 were important ones. Sysf/uypi/s has, as is kown, either two or 

 three submarginal cells. The four species known t ) me all have two, 

 so that I cannot say but that there are other differences between 

 those with and those without the third. Loew, however, did not 

 deem the character snfficient to separate the species. Schiner takes 

 him to task, and asserts that he had confounded two genera, but in 

 this I think that he was unjust. He was disposed to believe that the 

 character was the decisive one bet>/een Dolichomyia and Sxstropus, 

 but in this he was in error; the character has not even a specific im- 

 portance as the specimens of the above described species conclus- 

 ively show. The real differences between the two genera are as 

 follows: 



Eyes of female dichoptic in DoIicJioviyia; antennas shorter than the 

 head; thorax less convex above; abdomen cylindrical and not at all 

 thickened at the extremity. 



It has only been recently shown that the eyes of Systropus are hol- 

 optic in both sexes,* one of the very few forms among diptera in 

 which such is the case. This is sufficient evidei:ice that Loew had 

 jiever seen DoUciioiiiyia in nature, for he was the first to suspect that 

 the eyes of the female of Systropus are contiguous. There are, then, 

 ibut three species of Dolichomyia known, D. nigra \\\t(\.. from 

 ■Columbia, D. dctccta Schiner from Chile, and the one above de- 

 scribed, which is closely allied to D. nigra. 



Coquillett, in his most recent paper on the genera of Bonilyliidu-',* 

 rejects several genera with three submarginal cells, but, to be con- 

 sistent, he should have rejected his own, based chiefly upon that very 

 character. One may expect to find that Rhabdopselaphus Bigot, and 

 Triplasius Loew (a North American genus which Coquillett seems to 

 have entirely overlooked) are inconstant in this particular, and con- 

 sequently untenable. But, although I have made no particular study 

 of the genera of the Bombyliidir, I do not feel so sure that Coquillett 

 will be generally followed in his rejection of Osten Sacken's genera. 

 •Osten Sacken has made an especial study of the Bonihyliida-, and his 

 .appreciation of generic characters is altogether too acute to be 

 lightly disregarded, certainly not without giving proof. It is prob- 



*Osten Sacken. 



tTrans. Am. Eiit. Soc, xxi. S9. 



