ART. 17. NORTH AMERICAN PHOROCERA ALDRICH AND WEBBER. 41 



both sexes four and one-half times the second, arista a little thick- 

 ened on basal third, the penultimate joint short. Thorax black, gray 

 pollinose, marked with four black vittae and bearing four dorso- 

 central macrochaetae ; scutellum black «t base, gra.y pollinose, the 

 tip yellowish, bearing three long pairs of marginal and a shorter 

 backward turning pair of apical ones. Sternopleura with three 

 strong bristles. Abdomen thick, the fourth segment short, and deep : 

 abdominal color black, gray pollinose, especially so at base of seg- 

 ments two and three, fourth segment somewhat yellowish in some 

 specimens, gray pollinose in most. Discal macrochaetae on the inter- 

 mediate segments or at least the third, two rows on the fourth, one 

 at the apical half, the other a weaker row at the apex; abdominal 

 hairs depressed. Legs black, sometimes brownish, mid tibiae with 

 one strong bristle on the outer side near the middle: hind tibiae 

 ciliate, with one longer bristle. Third vein with four or five bristles 

 at its base. 



Length 10 to 12 mm. 



Redescribed from the type and several specimens of each sex, the 

 material from New England and Washington, D. C, the latter bred 

 from Sarrothri'pus revayanus Scopoli (Walton MS). 



ry;?e.— Female, Cat. No. 8592, U.S.N.M., from Franconia, New 

 Hampshire. 



ZENILLIA CEBATOMIAE Coqnillett. 



Exorista ceratoiniae Coqtjillett, Revis. Tnchin., 1897, p. ]01. — Reinfiakd, 

 Ent. News, vol. 32, 1921, p. 72. 



Front of male 0.27 to 0.30 (in three), of female 0.33 to 0.36 (in 

 ihree) of the head width; front and face silvery pollinose. the former 

 bearing many short inconspicuous hairs; front in both sexes higher 

 and more convex in profile than in the nearest relatives; frontal 

 bristles reach the third antennae joint, the two uppermost ones 

 stout and reclinate; facial ridges bristly on the lowest fourth, some- 

 times one-third of the way ; palpi yellow with black hairs, not par- 

 ticularly dense; bucca one-sixth the eye height, bearing but a few 

 fine hairs on the lower half besides the stout black bristles on th>? 

 lower border; antennae nearly as long as the face, first and second 

 joint yellowish, the third blackish, about four and one-half time? 

 the second in the male, somewhat shorter in the female: arista con 

 siderably thickened on the basal third, the penultimate joint short. 

 Thorax black, thickly gray pollinose. marked with four black vittae. 

 the outer ones broken at the suture ; four dorsocentral macrochaetae : 

 scutellum thickly gray pollinose with four pairs of marginal bristles: 

 in the female the apical pair aie sometimes absent, all bristles are 

 directed backward; sternopleura gray pollinose, thickly clothed with 

 fine hairs, and with three stout bristles. Abdomen, excepting the 



