OF THE TABANID^ OF THE UNITED STATES. 379 



disli at base. Thorax black ; a broad, glaucous intermediate stripe is divided in two by a 

 black longitudinal line ; on each side a glaucous-grayish stripe runs above the root of the 

 wings, from the scutellum to the humerus ; a blackish strij^e separates it from the glaucous- 

 grayish pleurse ; the latter glaucous-grayish, with a black stripe. Scutellum blackish. Ab- 

 domen black; first two segments pale grayish-yellow (livid) on the sides, black in the mid- 

 dle ; the Ijlack on the second segment has somewhat the shape of a A, the middle triangle 

 of this f5o;ure being of the same color as the sides of the abdomen ; both ends of this fif^ure 

 expand laterally in the shape of small Ijlack triangles, resting upon the hind margin of the 

 segment ; the following segments are black, with a narrow gray posterior border, expanding 

 into a triangle, with two adjacent gray marks ; these triangles and marks are especially vis- 

 ible on segments 3-5. Wings : root, costal cells and crossband brown ; beyond the cross- 

 band a narrow pale brownish cloud along the costa nearly reaches the tip of the wing ; 

 the crossband does not reach the posterior margin, the distal end of the fourth posterior 

 cell being colorless, the last section of the fifth vein enveloped in a brownish cloud, con- 

 nected with the crossband across the proximal end of the fifth posterior cell ; the apex of 

 the wing is grayish, with a very distinct whitish halo between it and the crossband ; similarly, 

 a brownish shadow in the anal angle of the wing renders more apparent the whitish-hyaline 

 tinge of the two basal and of the proximal end of the anal cell. Legs variable in coloring ; 

 either red, tips of front and hind tibia?, front tarsi, and last four joints of the four posterior 

 tarsi, blackish ; or black, bases of middle tiljia? and of the four posterior tarsi, reddish ; with 

 all the intermediate stages. 



Hob. Red River of the North (Kennicott) ; Illinois (LeBaron) ; Wisconsin (v. d. 

 Wulp) ; Dacota (Dr. Coues). 



The extent of tlie yellow color on the abdomen is variable in this species. I have a spec- 

 imen before me ( Red River of the North ) where the small black triangles on the second 

 segment have their apex prolongetl so as to meet the black on the corresponding side of 

 the first segment. In another specimen (Illinois) with very dark legs, the yellow on the sides 

 of the abdomen is replaced by a glaucous-gray, the black design of the first two segments 

 being the normal one. 



Mr. van der Wulp's description and figure are excellent, and refer to the variety with 

 the darker feet. Mr. Walker's description is very mcomplete, and is rendered still more 

 doubtfid by the locality (Nova Scotia) ; all the specimens of C. cestuans hitherto received 

 come from the Northwest. 



9. Chi-ysops callidvis n. sp. 



? . Apical spot in the shape of a narrow linear brown border along the costa; both basal icells hyaline ; 

 (liscal cell filled out with brown ; no small black triangle on each side of tlie A-shaped black spot on the sec- 

 ond abdominal segment. 



c5 . Wings as in the $ , but both basal cells infuscated, with a common hyaline spot at the distal end. 



Length, 8-9 mm. 



Female. Head, antenute and picture of the thorax as in C cesfiicms ; the lateral strijDCs 

 on the thorax and the pleunx; are more yellowish than glaucous ; palpi more reddish. Ab- 

 domen black ; first two segments pale yellow on the sides, black in the middle ; the black 



