28 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.63. 



logo) fuiniferaiia Clemens as a common host in Canada. At the 

 gypsy moth laboratoiy it has been reared again from Pieris rapae 

 Linnaeus. 



ZENILLIA CAESAR Aldrich. 



Exorista nigripalpis Townsend, Psyche, vol 7, 1896, p. 330, not of Mac- 

 quart, 1846. — CoQuiLLETT, Revis. Tachin., 1897, p. 93. — Gibson, Rept. 

 Ent. Soc, Ont., for 1918, p. 117.— Greene, Proc. U. S. Nat. Mus., vol. 60, 

 art. 10, p. 11, 1922 (puparium). 



Exorista eaesar Ai,deich, Canad. Ent, vol. 48, 1916, p. 20. — Caesar. 46th 

 Rept. Ent Soc. Ont., 1916, p. 173. 



Front of male 0.27 to 0.29 (in three) and in the female 0.31 to 

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

 the former blackish at vertex; biicca one-sixth the eye height; 

 facial ridges bristly on the lowest third; antennae variable in length, 

 sometimes reacliing the oral -margin but usually about five-sixths the 

 length of face; third joint in male varying from two to three and 

 in the female from one and one-third to two and three-quarters 

 times the second; arista thickened on the basal third the penulti- 

 mate joint usually elongate. Wliile this character is not a constant 

 one it will hold true in the majority of forms. Thorax black, thinly 

 gray pollinose bearing four dorsocentral macrochaetae ; scutellum 

 black with three long and one short apical pair of bristles, the latter 

 pair curving backward ; sternopleura with three bristles. Abdomen 

 black, somewhat shiny, the bases of the last three segments lightly 

 gray pollinose, the fourth nearly always shining black; discal 

 macrochaetae present on the intermediate segments, the fourth 

 wholly bristly excepting the base ; abdominal hairs suberect in male, 

 depressed in the female. Mid tibiae with one or two bristles on the 

 outside near middle; hind tibiae ciliate with one longer bristle. 

 Third vein with one or two bristles at base. Hypopygium black, 

 inner forceps decidedly longer than the outer ones, in profile they 

 are rounded outwardly at base, concave near the middle and then 

 curving inward and ending in a slender point; outer sides sparsely 

 haired; outer forceps shorter, about three-fourths as long as the 

 inner ones terminating in a blunt point, their base yellowish. 



Redescribed from a long series of specimens; three paratypes of 

 ceasar, reared from Gacoecia argyrospila Walker at Simcoe, Ontario, 

 by Prof. Lawson Caesar; a series reared at Canyon City, Colorado, 

 by J. B. Gill, from the same host; one from Loxostege sficticalis 

 Linnaeus at Greely, Colorado, by A. E. Mallory; several from 

 PyrauHta nuhilalis Huebner at West Medford and neighboring 

 places in Massachusetts; several reared from Gramhus tnsectus 

 Walker at Lafayette, Indiana, by W. H. Larrimer; collected speci- 

 mens from New England: Tennessee Pass. Coloj-ado: Koehler, New 

 Mexico. 



