TABANID^ OF OHIO. 41 



branch of the fifth vein is plainly margined on both sides with brown 

 and this margin communicates more or less with the cross band across 

 the fifth posterior cell ; the first abdominal segment has a rather obscure 

 dark patch beneath the scutellum, the second has two elongate oblique 

 black spots connate anteriorly, and sometimes on either side near the 

 posterior margin a very small additional spot ; the third and fourth each 

 have four black spots, and in some specimens five has likewise, but 

 usually five, six and seven are uniformly black on the whole anterior 

 part ; all the segments behind the first are narrowly margined with yellow ; 

 ventrally, abdomen yellow with apex and narrow lines on the sides of 

 some of the segments blackish. 



Male: Both baisal cells infuscated except a small hyaline patch at 

 the apex of each; the first segment of the abdomen is blackish with the 

 exception of a yellow posterior margin which is slightly expanded on 

 either side, the second has a large quadrate black spot in the middle 

 enclosing a small yellow triangle posteriorly and on each side a narrow 

 longitudinal spot also black ; three and four are colored like two ; the seg- 

 ments behind the second are plainly margined posteriorly with yellow 

 and five, six and seven are uniformly black in front. These markings- 

 form a wide longitudinal black stripe in the middle of the abdomen 

 enclosing small yellow triangles on segments two to four, and on each 

 side of this a much narrower black stripe followed by a still narrower 

 black stripe. Hitherto this sex has not been described. 



Habitat : Northern and Southern Ohio. 



I have never found the species common except at Cincin- 

 nati in the region of a series of small artificial lakes. Here the 

 females were very persistent in attacking me, and I procured 

 males by sweeping the plants that grew along the edge of one of 

 the lakes. 



■ GHRYSOPS NIGER Macquart. 



Length 6-8 mm. First segment of antennae yellow, face yellow 

 with cheeks and facial callosities black ; body and legs except the metatarsi 

 and part of the following segment on the middle and posterior pairs, black; 

 apex of wings beyond the cross band hyaline. 



Female : First basal cell of wing brown except a small spot near the- 

 apex bordering the fourth longitudinal vein, second basal hyaline; the 

 cross band nearly fills out the fourth posterior cell but does not enter the- 

 fifth posterior; the very narrow hyaline apex of . the fourth posterior cell 

 varies slightly in width in different specimens. 



Male : Colored like the female except only a small spot at apex 

 of the second basal cell is hyaline, and the fifth posterior, except at 

 extreme base, and anal cells are dimly infuscated. 



Habitat : A common species in Ohio and one of the earliest 

 to appear in spring. 



The entirely hyaline second basal cell distinguishes the female 

 of this species from all others of its group. The small size of the 

 hyaline spots in the apex of the basal cells are characteristic of 

 the male. The hyaline spot of the first basal is very small and 

 borders the fourth vein. 



