OF THE TABANID^ OF THE UNITED STATES. 395 



3. Chrysops quadrivittatus Say, J. Aca.l. Phil., m, 33, 1 (1822) ; Wictl., Auss. Zweifl., i, p. 200, 9. 

 Rocky Mts. 



4. Chrysops sepulchralis Kirby, Fauna Bor. Amer., p. 314, 1. 



Whether it is really identical with Fabricius's species of that name, remains to be proved ; 

 this identification certainly shows that the species belongs to the group provided with an 

 apical spot. 



SILVIUS. 



The only North American species of this genus hitherto described, S. isahelUnus Wied., 

 I have never seen. The following species is a true Sllvius from the Pacific basin ; it differs, 

 however, from the European species in the presence, on the flice, of shining black callosi- 

 ties. 



Silvius trifolium n. sp. 



$ . Thorax clotlicd wltli a dense yellowish pollen, abdomen reddish-yellow, at the base with three elon- 

 gated blackish spots, connected at their ends in the shape of a clover-leaf. 

 Length 11.5 mm.; wing 10.5 mm. 



Head grayish-yellow, from a dense pollen A^;^hich covers it; small area)( round the ocelli, 

 an obcordiform frontal callosity and two «ig«W- spots on the face, below the antenna?, shin- 

 ing l)lack. Antenna? : two basal joints and base of the third, reddish-yellow, the remainder 

 black ; palpi reJdish-yellow. Thorax : ground color black, but altogether concealed under 

 a thick grayish-yellow pollen ; pknu-a? with yellow hairs. Abdomen reddish-yellow, some- 

 what purer yellow on the posterior margins of the last segments, clothed with some ap- 

 pressed minute black hairs ; the posterior margins of the segments show traces of a frino-e of 

 yellow hairs; the first segment has a blackish spot in the shape of a recumbent, elonoated 

 8, both lobes of which are situated on both sides of the scutellum ; on the second sefment 

 in the middle, there is an elongated spot of the same color, which, with the spots of the 

 first segment, forms a figure not unlike a clover-leaf; these spots are clothed with yellow- 

 ish pollen. Venter reddish-yellow, with a trapezoidal black spot at the base. Feet reddish- 

 yellow ; knees, tibia? and tarsal joints tipped with brown : tarsi altogether brownish towards 

 the end ; himl tibite beset with black hairs. Wings hyaline witli a grayish tinge ; the base, 

 the costal areas and stigma tinged with yellow ; the fork of the third vein has a stump of a 

 vein. 



Vancouver Island (G. R. Crotch); Washington Territory. Two female specimens. 



HzEMATOPOTA. 



Besides H. punctulata Macq., Dipt. Exot., i, 1, p. 163, from the Carolinas, which I do not 

 know, the following species occurs in North America, and seems to be very common in the 

 Northwest. 



Hsematopota americana n. sp. 



F~imde. Grayish-black, v.ariegated with white lines and spots; wings grayish, with ninnerius irre<TiiIar 

 whitu streaks and a large ocellar spot, having tiie b.ase of the second posterior cell for its centre. Antennre 

 blask, firs'^ joint very much incrassated, the thin! somewhat i)ale at the extreme base only ; a large, shiniii'T, 

 black, tr.insverse callosity above them; two velvety black spots above the callosity. Feet black ; front tibia; 



