110 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxv. 



OESTROPHASIA SETOSA, new species. 



Female. — Differs from calva as follows: Mesonotuni with a trans- 

 verse row of three black spots behind the middle, fourth abdominal 

 segment black on more than the apical half, base of first segment black 

 in the middle of upper edge, a In-oad black dorsal vitta, passing over 

 the broad Ijlack hind margins of the first three segments; second 

 segment bearing a scattered median cluster of eight bristles which 

 extends nearh' to the middle of the length of the segment, third with 

 a cluster of eight in front of the marginal row, the fourth covered 

 except at the base; third vein bristly almost to the small crossvein; 

 length, 6 mm. A female specimen collected b}^ H. K. Morrison. 



Ilabltat. — Colorado. 



Type.—Q^i. No. 6210. U.S.N.M. 



EXORISTOIDES HARRINGTONI, new species. 



Black, the face and apex of proboscis yellowish, first two joints of 

 antennae and the palpi yellow; vertex one and one-half times as wide 

 as either eye. one pair of orbital bristles and between each bristle and 

 the frontals is an outwardly directed bristle, frontals descending to 

 the arista, the latter thickened on the basal half, the pemdtimate joint 

 shorter than broad, antenna? nearly as long as the face, the third joint 

 five times as long as the second, eyes sparsely hairy, cheeks one-third 

 as wide as the eye height; thorax grayish pruinose, the vitta? indis- 

 tinct, three pairs of postsutural dorsocentral bristles, three sterno- 

 pleurals, scutellum bearing four marginal pairs, the last pair cruciate; 

 abdomen polished, the bases of the last three segments grayish ])rui- 

 nose, these segments bearing discal and marginal bristles; wings hya- 

 line, a gray cloud at base of discal cell, a brown crossband extends from 

 apex of first vein to slightly below the small crossvein; first vein 

 wholly bristl3% the third from its base to beyond apex of discal cell, 

 first posterior cell closed and short petiolate, ending slightly before 

 apex of wing, bend of fourth vein rectangular and with a short stump, 

 hind crossvein nearer the small than to bend of fourth; calypteres 

 whitish ; length, 4 mm. A female specimen collected by Mr. W. Hague 

 Harrington, for whom this fine species is named. 



Ilahifat. — Ottawa, Canada. 



7]/j>6.— Cat. No. 6211, U.S.N.M. 



EXORISTA TRISETOSA, new species. 



Black, including the palpi; vertex of male one and one-half, of 

 female twice, width of either eye, two pairs of orbital bristles in 

 female, frontals descending to the arista, antenna^ slightly shorter than 

 the face, the third joint two and one-half times as long as the second, 

 arista thickened to the middle, facial ridges bristlj^ on the lower two- 

 fifths, cheeks one-fifth as wide as the eye height; proboscis rather 



