146 DIPTERA OP NORTH AMERICA. [PART III. 



known is not metallic. The peculiar venation distinguishes these 

 species from all the others of the present group. The typical 

 species is D. lutulenta Loew (Berl. Entom. Zeitschr. XI, 285; 

 Tab. II, Gg. 1), from Surinam. 



No Dasymetopse from North America are as yet known. 



Gen. II. OEDOPA Loew. 



Charact. — Head conspicuously large ; front unusually broad ; ocelli on the 

 edge of the vertex, very closely approximated. 



Antenna very short and very distant from each other; third joint 

 rounded, with a thin, bare arista ; frontal fissure running in an 

 almost straight line from antenna to antenna; no frontal lunule. 



Face broad, somewhat convex, with a small excavation under each 

 antenna ; its lateral portions conspicuously broad, distinctly 

 separated from the middle portion. 



Eyes rather round, but somewhat broader than high, comparatively 

 small, hardly reaching the middle of the height of the head ; hence, 

 the cheeks unusually broad. 



Clypeus not horseshoe-shaped and thus surrounding the proboscis, 

 but lobiform, connate with the anterior edge of the comparatively 

 small oral opening ; proboscis small. 



Thorax with bristles on its hind part only; scutellum flat, with four 

 bristles. 



Wings: the last section of the fourth longitudinal vein, towards its 

 tip, is somewhat curved forward and thus convergent towards the 

 third vein ; posterior cross vein curved in the shape of an S; poste- 

 rior angle of the anal cell drawn out in an elongated point. 



The body appears very bare on account of the sparseness and 

 shortness of the hairs, as well as of the shortness of the bristles. 

 The structure of the head resembles somewhat that of some South 

 Asiatic Ortalidse, while similar American forms have, before 

 now, not been known. 



1. O. capito Loew. % £ • — (Tab. IX, f. 1-3.) Albicans, fascia frontis 

 tenui, thoracisque vittis nigris, in supero faciei margine maculis atris 

 tribus, lateralibus ovatis, media, didyma. 



Whitish ; front with a black transverse band, thorax with black longitu- 

 dinal stripes ; the upper margin of the face with three deep black spots ; 

 the lateral ones oval, the middle one double. Long. corp. 0.18 — 0.25; 

 long. a!. 0.15—0.22. 



Syn. Oedopa capito Loew, Berl. Ent. Zeitschr XI, p. 287, Tab. II, f. 2. 



Head yellowish-white, only the middle of the occiput somewhat 

 blackish; the ocelli are placed upon a punctiform black dot; the 



