302 ERNEST A. BACK. 



terior lateral margins with black bristles; the pile on the whole lateral 

 margin of the second segment and on the outermost lateral edge of 

 the third segment is white; the pile of the rest of the second and 

 third and of the following four segments is wholly black ; that of the 

 last segment whitish ; on each segment, beginning with the second, 

 there is a transverse row of perhaps four conspicuous black bristles. 

 The prevailing black and sharply-defined white hair of the legs is 

 arranged as usual; all the bristles are black. 



Type. — M. C. Z. A single female type specimen from 

 Canada (Provencher) . 



Habitat.— Cannula.; White Mts., N. H. 



Osten Sacken has named a male and a female Lasiopogon 

 from the White Mountains opaculus with a question mark. 

 They are not opaculus. I believe they are tetragrammus. 

 They agree with the type of the latter in size, general colora- 

 tion of abdomen, but the genitalia are rather larger, grayish- 

 brown pruinose, with black pile. 



Lasiopogon quadrivittatus. 



Lasiopogon quadrivittatus Jones, Trans, Am. Ent. Soc., XXXIII, 

 278, 1907. 

 "9. — Length 9-11 mm. — Near L. arenicola O. S. Black; covered 

 everywhere with a dense grayish bloom. Front broad, densely gray 

 pruinose; hair everywhere whitish; that of the occiput with a more 

 decided yellowish tinge, beard and hair on occipital margin fine, silky 

 and purer white. Face in profile with a strong gibbosity reaching more 

 than half the distance from the oral margin to the base of the antenna?. 

 Antennae black; first two segments nearly equal; second a trifle longer 

 than the first; the third longer than the first two taken together; 

 style about one-half as long as the third segment; first two segments 

 of the antennas with whitish hair. Thorax black, covered with dense 

 grayish bloom and very fine white pile; a few light colored bristles on 

 the lateral margins and posterior part of the dorsum; four brownish, 

 nearly median stripes on the dorsum, diverging anteriorly, the bloom 

 on the lateral margins brownish, forming an obscure stripe. The 

 interval between the inner stripes is wider than that between the 

 others, so that there appears to be two geminate stripes. Scutellum 

 flat, covered with a bloom similar to that of the thorax, and with a 

 row of light colored bristles on the posterior margin. Bloom of the 

 pleuras gray, with a brownish tinge. Halteres yellowish, the trichostical 

 hairs white. Abdomen black, covered with dense grayish bloom and 

 very fine, short, decumbent whitish pile; anterior margins of the 

 second, third and fourth segments reddish-brown; last segment pol- 

 ished black. Bristles on the posterior margins of the first segment 



