6 Myron Harmon Sivenk 



pleura black; valves of pygidium subuniformly rounded on apical mar- 

 gin, the dorsal valve distinctly exceeding the ventral valve; lo mm. 



pulchra 

 (The male of 5. pulchra is unknown.) 



Stelis (Chelynia) pulchra Crawford. 



1902. Stelis pulchra Crawford, Canadian Entomologist, XXXIV, pp. 



239-240, $. 

 1907. Chelynia pulchra Cockerell, Univ. of Colorado Studies, IV, p. 



249, ?. 



Known as a Nebraska bee only from the type, a female collected 

 in Warbonnet canyon, Sioux county, June 28, 1901, by J. C. 

 Crawford, and subsequently described by him. When captured 

 the bee was flying over gravelly ground. Mrs. W. P. Cockerell 

 has captured this species at Boulder, Colorado, on a small 

 Astragalus. 



SPECIES FROM OUTSIDE NEBRASKA 



Stelis (Chelynia) subemarginata Cresson. 



1878. Stelisf suheinarginata Cresson, Trans. Am. Ent. Soc, VII, p. 



93, ?. 

 1898. Stelis. subemarginata Cockerell, The Entomologist, p. 167. 



A female from the Big Horn mountains before the writer, 

 taken at 8,000 feet in August 1894, agrees with Cresson's descrip- 

 tion of subemarginata in all essential details. The two cotypes 

 of subemarginata came from Colorado. 



Stelis (Chelynia) idahoensis n. sp. 



$. Length 10 mm. Shining black. Head and thorax closely punctured, 

 the punctures rather coarse. Pubescence erect, rather thin, pale, on face 

 above and on mesopleura copiously mixed with black. Antennal joint 3 

 above subequal to 4, below slightly exceeding 4. Wings slightly darkened; 

 especially apically, nervures dark brown, second submarginal cell not over 

 one-fourth longer than the first, both recurrent nervures received within 

 this cell. Legs thinly clothed with black hairs, the inner sides of the 

 tarsal joints with reddish golden pubescence. Abdomen shining black, 

 sparsely punctured except along basal margins of the tergites, tergites 

 1-5 with transverse, narrow, complete, yellowish white bands, all narrowed 

 medially and slightly but sharply incised medially on anterior margin on 

 3-5, on 1-4 attaining the sides of the tergite and laterally produced down- 

 ward in a swollen termination while the lateral posterior margin is broadly 

 emarginate, on 5 abbreviated and terminating acutely laterally. Tergites 



6 



