496 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



clypeus; the band has in front a large, pale, grayish-brown patch, with 

 the sides at first nearly parallel, then in the middle this patch is slightly 

 dilated and rounded, at last triangularly narrowed, almost wedge- 

 shaped, not much pointed; a little behind its apex, and commencing 

 from the central furrow, is a little black triangle, or short line, tapering- 

 backward. The sides of the cephalothorax, on each side of the middle 

 band, are brown, the extreme lateral margin white ; each of these brown 

 side-bands ends behind with two rather large black spots, separated by a 

 white spot or short broad line. The sternum 3bud parts of the mouth are 

 grayish-white, somewhat mottled with brownish. The legs are grayish- 

 white, densely mottled with brown and black points ; the four ante- 

 rior ones are brownish above, with a whitish longitudinal line reach- 

 ing to the end of the tibise; the thighs of the first pair have a few 

 more conspicuous small black spots in front, above ; the 4 hinder legs 

 are grayish, with a white line above, and spread with smaller and larger 

 black spots, which form a broken ring or transverse band toward the 

 apex of the thighs above; two such rings on the patellae and tibiae (and 

 at least traces of two rings on the metatarsi), one at the apex, the other 

 at the base ; the anterior metatarsi and tarsi are brownish-gray, without 

 rings. The back of the abdomen is along the middle whitish-gray, 

 strewed with small black points, and brown in the sides ; the whitish- 

 gray middle band is double as broad (about 2 millim.) as the brown 

 side-bands, slightly dilated behind the middle, and then tapering, its 

 posterior portion being coarsely dentated in the margins ; the sides of 

 the abdomen and the belly are whitish-gray, somewhat brownish in the 

 side-wrinkles ; the belly shows two rows of brownish points ; on the outer 

 side of the pulmonary shields are two black spots, the posterior nearly, 

 ring-shaped, open inward. The vulva is black, the mamillce grayish- 

 white ; the hairs and bristles of the body are black, the spines on the 

 upper part of the legs also black, on the under part pale brownish, at 

 least on the anterior legs. 



Length of body 6J, of cephalothorax 3^ milliiu. ; breadth of cephalo- 

 thorax 3, of clypeus If millim.; length of abdomen 4J, greatest breadth 

 of same 3§ millim. Length of legs : I 9i, II 8f , 111^5, IV 7, of pat. -f tib. 

 I 31, of pat. -f tib. IV 2^ millim. 



A single female specimen of this species was captured at Boulder, 

 Colo., June 29. It is very nearly related to X. cristatus (Clerck) and its 

 European allies, but may, I think, be without difficulty distinguished by 

 the marks in the above description. Thorn, ferox Hentz (1. c, v, p. 445, 

 pi. xxiii, fig. 3) appears also to be a closely related species. 



Gen. OxYPTiLA Sim., 1864. 

 14. 0. conspurcata n. 



Cephalothorax as long as patella + tibia of the first pair, equably and 

 finely coriaceous, provided with clavated bristles on the clypeus, dark 

 brown, with a longitudinal rusty-brown middle baud and an irregular 



