498 BULLETIN UNITED STATES GEOLOOICAL SURVEY. 



also each a paler, irregular, longitudinal band, composed of rusty-brown 

 spots ; the extreme lateral margins are of a rusty testaceous hue. Ster- 

 num, maxillce, and labium pale rusty-brown, the maxillse whitish at the 

 apex; the mandibles dark, with rusty-brown spots. Palpi and legs 

 blackish-brown, pale at the base ; the coxse are of a pale grayish testa- 

 ceous color, as is also the base of the thighs, especially of the hinder 

 legs, which are rather paler than the two anterior pairs, and in which 

 both tibiae and metatarsi have a blackish ring near the base. Abdomen 

 grayish- brown above, mottled with black, these black markings form- 

 ing a large patch occupying the greatest part of the back behind ; 

 toward the sides, the abdomen is also strewed with small whitish points ; 

 the sides and belly are dusky or sooty gray, the vulva pale, with excep- 

 tion of the two larger lateral tubercles, behind, which are brown. The 

 mamillce are pale grayish. The hairs and bristles of the body and the 

 extremities are blackish, with exception of the appressed bristles of the 

 cephalothorax, these being rusty-yellow : the long spines on the under 

 part of the fore tibia and metatarsi are pale brownish. 



Length of body nearly 4 millim. ; length and breadth of cephalo- 

 thorax If millim.; length of abdomen 2^ breadth of same 2^ millim. 

 Length of legs: I 4^, II nearly 4|, IH 3, IV 3^ millim.; patella + 

 tibia I 1^ millim. 



Of this species, which is closely allied to the European 0. praticola 

 (0. L. Koch) and others, a single female specimen was captured at 

 Manitou Springs, Colo., July 13. 



Gen. Di^A Thor., 1870. 

 15. D. lepida n. 



Cephalothorax brownish testaceous, with two brownish longitudinal 

 bands toward the sides ; area occupied by the central eyes somewhat 

 broader than long, scarcely broader behind than in front ; legs testa- 

 ceous, at least the second pair, with broad brownish-red rings at the 

 apex of tibia, metatarsi, and tarsi ; upper part of abdomen pale grayish- 

 brown, whitish toward the sides, with two converging, dentated, red- 

 dish-black bands on its posterior half; tibial joint of the male's palpi 

 broader than long, oblique, its outer side at the apex drawn out into a 

 forward- directed, pointed process, as long as the joint itself. — S ad. 

 Length about 2§ millim. 



Male.— Cephalothorax fully as broad as long, strongly and equably 

 rounded in the sides of the large pars thoracica, sinuated just under the 

 hind lateral eyes ; the pars cephalica broad, its free part very short, 

 rounded in front ; the height of the perpendicular clypeus somewhat 

 smaller than the length of the area occupied by the central eyes. 

 The front row of eyes rather slightly curved upward, the hind row 

 more strongly curved backward ; the distance between the two lateral 

 eyes, which are placed on a common low and broad ridge, or long tuber- 

 cle, is much greater than that between the fore and hind central eyes. 



