2 26 The Ohio Naturalist. [Vol. V, No. 2, 



Chrysops surdus Osten Sacken. Somewhat like proclivis but 

 smaller. The facial callosities are black on both sides of the 

 suture leaving a narrow yellow stripe on the middle of the face. 

 The male is darker than the female and much like the male of 

 proclivis in general appearance. However, the same characters 

 which separate the females may be used in regard to the males. 



Chrysops virgulatus Bellardi. Although this species has not 

 been taken in the United States so far as I know, it seems best to 

 include it in treating our species with the first antennal segment 

 enlarged. Female 6 to 9 millimeters. First two antennal seg- 

 ments decidedly swollen, shining brownish, darkest above; third 

 segment with basal annulus decidedly yellow, remainder black, 

 slightlv longer than the second, but not so long as the third. 

 Ocellar area black, widely separated from the eve on either side; 

 legs yellow w4th the exception of the knees, apical part of front 

 tibiae and their tarsi and distal parts of other tarsi black or 

 brown. Wings with costal margin and cross-bands black, apical 

 spot rather wide, entirely filling out the marginal cell, the apex 

 of first submarginal and extending into the second submarginal. 

 The cross-band includes more than half of the first submarginal 

 cell and about half of the first posterior, not quite half of the 

 second posterior, and more than half of the third posterior, all of 

 the fourth posterior and discal, basal half or more of fifth posterior 

 and apexes of anal and first and second basal cells; basal two- 

 thirds of first basal and one-third of second basal also black; a 

 whitish area invades the hvaline areas on the outer and inner 

 margins of the cross-band. Abdomen black and yellow, black as 

 follows: An oblong patch beneath the scutellum, two or four 

 usually connected spots on anterior part of second segment, and 

 four oblong spots on each of the remaining segments separated 

 longitudinally by yellow. The black on all the segments may be 

 connected anteriorly and the last two segments may be alto- 

 gether black. Venter yellow with a wide median black stripe 

 and a narrower one on each side. 



The male is decidedly darker than the female, the hvaline 

 triangle of the wings is the same in both sexes, but the hyaline 

 in the basal and anal cells consists of a spot in each, and taken 

 together form a crescent, the spot in the anal cell being located 

 nearer the wing base; the whole axillary cell is smokv. 



Distinguished from related species by the short third antennal 

 segment and the bright yellow basal annulus of the same. Sev- 

 eral males and females taken at Guadalajara, Mexico, by Jesse 

 McClendon in June and July, 190)). The synonomy is by Wil- 

 liston and 1 believe it should be adopted. 



