46 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.63. 



6. Fourth abdominal segment with dense, deep-yellow pollen ; male with or^ 



(Unary hair on front and ocellar triangle parviteres, new species. 



Fourth abdominal segment gray or only a little yellpw-pollinose ; male 

 with dense erect hair on parafrontals and ocellar triangle 7 



7. Scutellum reddish except base; fourth abdominal segment with gray 



pollen : halisidotae, new species. 



Scutellum at most with slight indications of red at tip; fourth abdo- 

 minal segment with yellowish pollen flavicauda Van der Wulp. 



8. Abdominal hairs depressed (or if erect very short) 12 



Abdominal hairs erect; facial ridges bristly slightly over one-half 



way ; third antennal joint long and unusually wide to the apex 9 



Abdominal hairs erect on the second segment, depressed on the third ; 

 third antennal joint of normal shape; abdomen mostly shining black. 



subnitens, new species. 



9. AVith two sternopleurals tortricis Coquillett. 



With three or four sternopleurals 10 



10. Bend of fourth vein rectangular, apical cell almost closed in the mar- 



gin ; third vein with six hairs at base hamata, new species. 



Bend of fourth vein obtuse and broadly rounded ; apical cell more 

 widely open ; third vein with two or three hairs at base (if with four 

 sternopleurals see Zenillia loheUae Coquillett) 11 



11. Antennae black, abdomen of usual form noctuiformis Smith. 



Antennae broadly reddish, abdomen thick at apex in profile. 



pachypyga, new species. 



12. Hind tibiae unevenly ciliate on the outer side, with several longer 



bristles ; bucca one-fifth the eye height ; bend of fourth vein gen- 

 erally with a distinct fold 13 



Hind tibiae evenly ciliated, with at most one longer bristle ; bucca one- 

 fourth the eye height ; face conspicuously receding ; frontal bristles 

 overlapping those of the facial ridges; front pulvilli in male about 

 equal to the last three tarsal segments ; third vein with only 3 hairs 

 at base imitator, new species. 



13. Third antennal joint very long and very wide to the apex in both 



sexes 14 " 



Third antennal joint usually of moderate length, if long then it is not 

 uncommonly wide 16 



14. Usually two sternopleurals; inner forceps of the male united into a 



small central organ, slender at the tip, its basal part provided with a 



dense brush of hairs behind, which curve downward einaris Smith. 



Three sternopleurals ; male forceps without brush 15 



15. Abdomen of male strikingly elongated; inner forceps united into a 



slender and curved beak, its base suddenly widening into a portion 

 which is deeply grooved behind, the groove full of dense, soft, pale 



hairs coccyx, new species. 



Abdomen of male not elongatetl ; inner forceps united into a rather 

 straight beak, which is deeply grooved behind on the apical half; and 

 turned forward at the tip sulcata, new species. 



^ Alia would run to this number. It is known only from a damaged female which has 

 unusually dense, white pollen, and an elongated abdomen. See description. Locality, 

 Tampico, Mexico. (Towusend, Proc. Biol. Soc. Wash., vol. 30, 1917, p. 50. > 



