of the Family 'Tabanide. 293 
tubercle which rises out of a triangular depression; there 
are also two black shining spots each side of the antenne ; 
the cheeks are finely punctured, with a longitudinal furrow 
ending in a cavity; there is some slight light-coloured 
pubescence on the face. Palpi greyish yellow, rather large, 
broad at base, tapering to a point; the first joint is short, 
the second has a longitudinal furrow. Beard grey. Pro- 
boscis as long as head. Eyes bare. Abdomen with the first 
two segments largely reddish yellow, with a black dorsal 
stripe, the remainingsegments are black, the posterior borders 
yellow; in some of the specimens the yellow border is wider 
than in the others. Legs yellow, with the apex of the 
posterior femora, the base of the fore tibiz and the tarsi 
black; the posterior tarsi are yellow with the apex of the 
joints darker. Halteres whitish. Wings hyaline, with pale 
yellow veins. Length 64 millim. 
The spurs on the hind tibiz in this species are small and 
easily overlooked. 
Type A. 20. 89. 65. 
Nearctic Region. 
*S. gigantulus, 9, Loew, Centur. x. p. 12 (1861); id. Berlin. ent. Zeit. 
xvi. p. 57 (1872) (Chrysops); Osten Sacken, Western Diptera, 
p- 215 (1877) ; id. Cat. N. Amer. Dipt. note 70 (1878). [S¢vius 
trifolium, Osten Sacken, Mem. Boston Soc. Nat. Hist. ii. p. 395 
(1876). |—California, British Columbia. 
S. pollinosus, 9, Williston, Trans. Conn. Ac. iv. p. 244 (1882); id. 
Trans. Kansas Acad. x. p. 131 (1887).—N. America. 
1. Third joint of antenne simple .............. 2. 
2. Yellow. Wings hyaline and non-pubescent.. gigantulus, Loew. 
3. Black, with greyish-white tomentum. Wings 
pubescent, clouded and spotted..... ...... pollinosus, Williston. 
Silvius gigantulus, Loew. 
Nine females from Chulukweyah Trail, British Columbia, 
August 1859. 
Neotropical Region. 
S. Sylvetrt’, 9, Macq., Dipt. Exot. i. p. 155, pl. xix. fig. 1 (1838) ; 
Walker, List Dipt. pt. v. Suppl. 1, p. 275 (1854).—(Called 
marginatus in Macquart’s plate, evidently a misprint.)—Brazil. 
S. rufipes, 2, Macq., Dipt. Exot. Suppl. 4, p. 87 (1850).—Brazil. 
S. nubipennis, 2, Rondani, Nuovi Ann. del Sci. Nat. Bologna, (3) 
ii. p. 371 (1850).—(This is evidently a female by the description, 
though not expressly mentioned.)—Iquatorial America. 
S. presbiter, S, Rondani, Archivio Canestrini, ili. p. 84 (1863); id. 
Ann. Soc. Nat. Modena, ii. p. 84 (1866) (Veprius).—St. Jago, 
S. America. 
S. rufopilosus, 3, Bigot, Mém. Soe. Zool. Fr. vy. p. 620 (1892) ( Veprius). 
—Chili. ! 
Ann. & Mag. N. Hist. Ser. 7. Vol. viii. 21 
