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



at the sides of the antennae are not so black or so thick as in your 

 specimen, and the forehead is not so dark." 



The specimen I sent Miss Ricardo measures fully 16 milli- 

 meters in length. As Bigot gives the length of his type as 11 

 millimeters, we see how misleading his statements may be. 



Tabanus sonomensis Osten Sacken. The antennae are black 

 or they mav be dark red at base, the third segment is narrow 

 with the basal portion longer than the annulate portion, and the 

 basal prominence is small; the palpi are brownish yellow clothed 

 with black hairs, the sides of the front in the female are nearly 

 parallel, the abdomen is plainly red on the sides. The usual dor- 

 sal row of gray triangles mav be seen in well preserved specimens 

 but no lateral rows are apparent. The red on the sides of the 

 abdomen is somewhat variable in extent, and the posterior mar- 

 gins of the segments are furnished with a fringe of yellow hairs. 

 The wings are hyaline but many of the veins, especially the 

 cross-veins and furcation of the third vein, are margined with 

 fuscous. 



The species is separated from rhombicus and its allies l)y the 

 nearlv complete absence of lateral gray spots on the abdominal 

 segments; and from affinis by the narrower third antennal seg- 

 ment, as well as its smaller average size, from epistatus by the 

 blacker antennae, and from phaenops by its larger average size 

 and clouding of the cross-veins and furcation of the third vein. 



The several males I have are colored like the females and 

 easily associated with them, although the fringes of hairs on the 

 posterior margins of the abdominal segments are not so conspic- 

 uous in this sex. Length 18 to IS millimeters. 



I consider haemaphorus Marten a synonym of sonomensis. 



Tabanus susurrus Marten. The antennae are red with the 

 annulate portion of the third segment black ; the wings are hya- 

 line btit there are faint clouds on the margins of the cross-veins 

 and at the furcation of the third vein. All the femora, the apex 

 of each anterior tibia, and the anterior tarsi are black or dark 

 brown, other paHs of legs red, except darker coloration on some 

 of the tarsal segments. The abdomen is red on the sides of the 

 first three or four segments. Specimens from Wyoming collected 

 bv Morrison. Marten's type was from Montana. Length 13 

 millimeters. 



Tabanus venustus Osten Sacken. This species is known from 

 all others of its genus by the large irregular dark patches on the 

 wings. Eyes naked. Length 14 to 1(1 millimeters. Taken as 

 far west as Oklahoma. 



Tabanus zonalis Kirl)y. This distinct species has the wings 

 uniformly tinged witli yellowish and the abdominal segments are 

 black anteriorly and broadly yellowish ])osteri()rly. The anten- 

 nae are red but the apex of the third segment may be black, y)alpi 



