34 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.63. 



which is often j^ellowish, bearing three long and one somewhat 

 shorter cruciate pair of apical bristles. Sternopleura with three 

 bristles. Abdomen black, subshining ; the last three segments thinly 

 gray pollinose except on the apices; discal macrochaetae present on 

 the intermediate segments, fourth segment bare at base, the apical 

 three-fourths bearing three rows of bristles; dorsal abdominal hairs 

 erect in the male, depressed in the female. Mid tibiae usually with 

 two bristles on the outer front side near the middle, sometimes a 

 third one is present ; hind tibiae with irregularly placed bristles of 

 uneven length. Third vein with two bristles at its base. 



Length 6 to 8 mm. 



Redescribed from the type, a male from University, North Dakota, 

 (Currie) and 18 other specimens: Dallas, Texas, and Milwaukee, 

 Wisconsin (collector unknown) ; Polk County, Wisconsin (Baker) ; 

 Big Stone City, South Dakota ; New Ulm, Minnesota ; Lake Meti- 

 goshe. Turtle Mountains, North Dakota; Moscow, Juliaetta, and 

 I>awyer's Canj^on, Idaho. All collected by the senior author except 

 as noted. 



r2/p<?.— Male, Cat. No. 3752, U.S.N.M. 



ZENILLIA AFFINIS Fallen. 



Tachina afflnits Fallen, Kougl. Svensk. Vet. Akad., vol. 31, 1810, and 

 Muscides, 1820, p. 28.— Meigen, Syst. Beschr., vol. 4, 1824, p. 327.— 

 Zetterstedt, Dipt. Scand., vol. 3, 1844, p. 1106. 



Exorista polychaeta Macquart, Annales Soc. Eiit. France, vol. 7, 1849. 

 p. 380. 



Exorista afflnis Meigen, Syst. Beschr., vol. 7, 1838, p. 255. — Coquillett, 

 Revis. Tachin., 1897, p. 94. — Adams, in Williston's Manual of N. A. Dipt., 

 1908, p. 358, fig.— ToTHiLL, Canad. Ent.. vol. 45, 1913, p. 70. 



Fourth segment of abdomen polished black, wholly bristly; mid 

 tibiae usually with three or more bristles on the outside near middle ; 

 male without orbital bristles. 



Front of male 0.26 to 0.27 (in three) , and in the female 0.31 to 0.32 

 (in three) of the head width; face and front silvery pollinose, the 

 latter blackish at vertex ; liead only a little longer at the base of the 

 antennae than at the vibrissae; parafacial at narrowest part one-half 

 as wide as the third antennal joint ; facial ridges bristly on the lowest 

 fourth or rarely third ; frontals extending to arista, the upper three 

 or even four reclinate ; bucca one-sixth the eye height ; palpi yellow ; 

 antennae shorter than face, the third joint in male two and one- 

 fourth and in the female about twice the lengtli of the second; 

 arista thickened on the basal fifth, the penultimate joint short. 

 Thorax and abdomen black, subshining, thinly gray pollinose, the 

 former indistinctly vittate, bearing three dorsocentral macrochae- 

 tae; scutellum yellow except the narrow basal margin, bearing three 

 pairs of long marginal bristles and a stout apical pair. Sternopleura 



