46 CYRTIDAE OF NORTH AMERICA 



"Hab. Dallas, Texas (J. Boll); a single male labelled 26, IX, which prob- 

 ably means September 26. 



"N. B. Wings resemble Pterodontia, on account of the expansion of the 

 costa. It may be this character is sexual. The profile of the body oiOpsebius 

 iPithogaster) inflahis figured by Loew, is exactly like this form." 



Professor Melander described this species from two males 

 from Austin, Texas, and one male from Rochester, Wisconsin. 

 "One of the Texas specimens was found under a stone, entangled 

 in a web of the Southwestern variety of Agelena naevia Bosc, 

 apparently just after issuing from the body of the spider. The 

 shriveled spider was lying close by, with a round perforation 

 near the base of the under side of the abdomen." 

 Opsebius dUigens (PI. VII, fig. 23.) 

 Opsebius diligens 0. S., Western Diptera, p. 278, (1876). 



"Of a shghtly metallescent brownish-black color, clothed with brownish- 

 yellow pile; legs browmsh -yellow; wings tinged with brownish, the tips hyaline; 

 first posterior cell divided in two by a cross-vein; the bases of the third and 

 fourth posterior cells nearly on the same line; anal cell closed and petiolate. 

 Length about 5 mm. 



"The venation is like that of the European 0. inflatus Lw.,^i ■with the follow- 

 ing differences: 1. The first posterior cell is divided in two (nearly equal) parts 

 by a cross-vein placed between the end of the discal and proximal end of the 

 second submarginal cell (the same character distinguishes the two North 

 American species described by Mr. Loew in the Centuries); 2. The third and 

 fourth posterior cells have their proximal ends nearly on the same Une; in other 

 words the insertion of the intercalary vein is coincident with the cross-vein at 

 the base of the fourth posterior cell; 3. The fifth vein runs straight to the mar- 

 gin, and the sixth is incurved toward it at a short distance from the margin. 

 The costa is distinctly thickened beyond the ends of the first and third veins, 

 and a little beyond the latter. The wing is distinctly tinged with brownish, 

 except at the base and the tip, which are subhyaline. 



"Body of a uniform brownish black, slightly metallescent on the thorax. 

 Thorax densely clothed with brownish-yellow erect pile, not dense enough, 

 however, to conceal the shining surface under it. On the abdomen, the same 

 pile is more dense on the second segment; the pile on the two intermediate 

 segments is more blackish, except along the posterior margins, where it is yel- 

 lowish; the fifth has a shorter and more appressed whitish-yellow pubescence, 

 interspersed with longer pile; the last segment is black, shining, rugose. Legs 

 brownish-yellow; femora slightly tinged with brownish; coxae, except the ex- 

 treme tip, brown. Halteres with a yellowish-white knob; tegulae semitran- 

 sparent, colorless. Eyes pubescent; antennae (broken)." 



Habitat. — Vancouver Island (G. R. Crotch). Two specimens. 



11 Wiener Entom. Monatschr., 1857, p. 33, tab. i, f. 1. 



