PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 82 



angles set high above lower border of head; 8 or 9 weaker and 

 shorter bristles below vibrissae, 1 pair decussate; vibrissal area 

 proper is glabrous, rather elongate, and narrowed, with few hairs 

 outside peristomal row to mark its separation from cheek-grooves; 

 vibrissal axis considerably shorter than antennal, latter about three- 

 fourths head height ; oral cavity shallow, rostrum recessive, haustel- 

 lum as long as antennae, labella knoblike and nearly as long as 

 haustellum, palpi only microstubs; antennae on eye middle, approx- 

 imated at base, very small and short, first joint flush, second very 

 short with 1 long bristle; third joint microseedlike, as long as sec- 

 ond, basal half inserted in latter; arista little longer than antennae, 

 scarcely longer than the bristle of second antennal joint, arising 



from middle of third antennal 

 joint, thickened only at base, 

 short-pubescent, basal joints 

 short; eyes bare, faintly oblique 

 on lower part, reaching vibrissal 

 level, facets equal; vertex one- 

 sixth head width ; front narrowed 

 to one-seventh head width on 

 middle, widening rapidly to one- 

 half head width at base antennae ; 

 face widening rapidly from 

 front, two-thirds head width at 

 level of lower border of eyes; 

 frontals stopping at base anten- 

 nae, weak, anterior one stronger, 

 6 or 7 in all, not hugging fron- 

 talia; inner verticals straight, 

 outer absent; no f ronto-orbitals ; 

 frontalia considerably narrowed posteriorly, nearly three times as 

 wide as one paraf rontal, smooth ; ocellar triangle reaching two-fifths 

 of the way to lunula, triangular, filling vertex, longer than wide ; only 

 2 ocelli, the front one absent; ocellars proclinate-erect, parallel, as 

 long as anterior frontals; postocellars weak, erect; postverticals 

 shorter than postocellars; paraf rontalia setose, faintly sloped an- 

 teriorl}^; paraf acialia equibroad, oblique to clypeal plane, as wide as 

 clypeus plus both facialia, outer one-third to one-half with erect 

 bristles, no f acio-orbitals ; cheek three-fourths the eye length; cheek 

 grooves rather large, facing forward, with 3 long prongs; no geno- 

 orbitals ; occipital area invading most of cheeks, its vestiture fine like 

 that of occiput. 



Infrascutellum well developed; lateral postscutellar plates, squamo- 

 pleura, prosternum, and propleura bare; prosternum moderately 



FiGDEH 1. — Oligooestrus oestroideus, new 

 genus and species : Head of male from 

 in fiont 



