216 BULLETIN UNITED STATES GEOLOGICAL SUEVEY. 



not the case with an ordinary Tabanus). Head rather large, very con- 

 vex anteriorly and concave posteriorly. In the male, the difference in 

 size between the large and small facets is considerable, the line of division 

 between them distinct; palpi ( ? ) stout at base; thirdjointof the antennae 

 rather broad, with a comparatively short, stoat, annulate portion ; upper 

 branch of the third vein knee-shaped at base, with a tendency to emit 

 a stump of a vein ; first posterior cell broadly open. (Species No. 5 pro- 

 visionally placed here until the male is found). "^ 



Tabanus^ in the broader sense, species Nos. 6 and 7. 



1. Tabanus procyon n. sp. — Is a Therioplectes ; eyes densely pubes- 

 cent, even in the female ; in life, they have four green stripes on dark 

 purple ground, the upper stripe not sharplj^ limited on the upper side. 



Female. — Altogether black ; subcallus black, shining, rather swollen ; 

 third antennal joint rather narrow. Length 13°^°^. 



Front broad, opaque, slightly grayish, clothed with black pile; cal- 

 losity large, broader than long, convex; subcallus denuded, shining, 

 somewhat swollen; cheeks black, shining, with long brownish hair; 

 antennPB black, third joint long and narrow, its upper corner hardly 

 projecting; ocellar tubercle distinct; palpi black, stoutat base; thorax 

 black, with long black pile, especially on the pleuroe ; abdomen black, 

 moderately shining; the two last segments with some whitish hairs; 

 legs black. Wings: — costal cell tinged with brown; bifurcation of the 

 third vein, cross- vein at the base of second posterior cell, also the central 

 cross- veins, more or less distinctly clouded with brownish. 



Hal). — Marin and Sonoma Counties, California, April, May. Two 

 females. 



Is somewhat like the European T. micans, but can be at once distin- 

 guished by the deep black color of the pile on pleurae and chest. 

 ^ 2. Tabanus sonomensis n. sp. — A Therioplectes of the group of T. 

 epistates (syn. T. socius of my Prodrome) and of the European T. 

 tropicus. — 



Female. — Grayish-black ; sides of the abdomen red ; abdominal inci- 

 sures fringed with yellowish hairs, which also form faint triangles in 

 the middle of the segments ; wings with a small but distinct brown 

 cloud on the fork of the third vein. Length 13-15™°^. 



Antennae black, sometimes fainty reddish on the second joint and at 

 the base of the third; the latter is not broad, its upper angle either mod- 

 erately or very little projecting. Front moderately broad, clothed with 

 browniah-gray pollen, and beset with black, erect pile; callosity large, 

 square, sometimes with a linear prolongation above ; subcallus not de- 

 nuded ; cheeks whitish, with yellowish-white hair ; palpi stout at base, 

 yellowish- white, beset with short black hairs ; eyes pubescent ; ocellar 

 tubercle distinct. Thorax grayish-black, the usual gray lines very faint ; 

 antealar tubercle reddish ; pleurae' thickly clothed with hairs of a dingy 

 gray. Sides of the abdominal segments 1 to 4 rufous, thus leaving between 

 them a black stripe, expanding anteriorly ; the remaining' segments black ; 



