ART. 17. NORTH AMERICAN PHOROCERA ALDRICH AND WEBBER. 13 



27. Front prominent; second and third abdominal segments satiny golden 



pollinose, the posterior fourth sharply divided, dull black and en- 

 tirely free from pollen ochracea Van der Wulp. 



Front not prominent ; second and third abdominal segments golden polli- 

 nose with shiny black hind edges which blend partially with the 

 golden marginata, new species. 



28. With two sternopleural bristles; fourth segment of the abdomen desti- 



tute of macrochaetae ; apices of the intermediate segments of the abdo- 

 men coucolorous angustivltta, new species. 



With three sternopleural macrochaetae; fourth segment of the abdo- 

 men with two rows of macrochaetae ; apices of the intermediate seg- 

 ments of the abdomen black marginata, new species. 



29. Head, thorax, and abdomen black, gray pollinose 30 



Head, thorax, and abdomen yellowish pollinose; second segment of the 



abdomen often destitute of discal macrochaetae helvina Coquillett. 



30. With four dorsocentral macrochaetae 32 



With three dorsocentral macrochaetae and three sternopleurals 31 



31. Males without oi'bital bristles ; third joint of the antennae in the male 



two and one-fourth, in the female about twice the length of the sec- 

 ond ; mid tibiae with three or more bristles on the outer front side near 



the middle ; discal macrochaetae not arranged in pairs afflnis Fallen. 



Males with orbitals ; third joint of the antennae in both sexes about 

 four times the second ; mid tibiae usually with but two long bristles 

 on the outer front side near the middle curriei Coquillett. 



32. With two sternopleural bristles 34 



With three sternopleural bristles 33 



33. Palpi swollen; abdominal hairs depressed; second antennal joint not 



especially elongated inflatipalpis, new species. 



Palpi normal ; abdominal hairs erect ; second antennal joint elongated. 



coerulea, new species. 



34. Abdomen covered with a thin bluish white pollen, narrow apical margins 



of the second and third segments shining black, their bases gray polli- 

 nose ; body and legs blackish, the tibiae often brownish ; face silvery ; 

 when viewed from behind the inner forceps are widely separated. 



reclinata, new species. 

 Abdomen, including the hind margins, covered with yellowish gray 

 pollen ; body and legs brownish ; face gi-ay pruinose ; when viewed 

 from behind the inner forceps are closely approximated. 



cheloniae Rondani. 



Subgenus Zenillia. 



ZENILLIA AMPLEXA Coquillett. 



Exorista amplexa Coquillett, Revis. Tachin., 1897, p. 97. 

 Eworista griseomicans Van deb Wulp, Coquillett, Revis. Tachin., p. 98. 

 Exorista flavirostris Van der WtXLP, Coquillett, Revis. Tachin., p. 100. 

 Sisyropa hemerocampae Townsend, Annals Ent. Soc. Amer., vol. 2, 1909, 

 p. 248. 

 Front in both sexes variable, in the male from 0.192 to 0.210 and 

 in the female 0.200 to 0.245 of the head width; front and face sil- 

 very pollinose, never with a strong yellowish cast; the sides of 



