THE CANADIAN ENTOMOLOGIST. 227 



A SUMMARY OF THE MEMBERS OF THE GENUS 



CHILOSIA, MEIG., IN NORTH AMERICA, WITH 



DESCRIPTIONS OF NEW SPECIES. 



P.V W. D. HUNTER, ASSISTANT IN ENTOMOLOGY, UNIVERSITY OF NEBRASKA. 



Cliilosia signatiseta, n. sp. 



Eyes bare, arista plumose, scutellum with long hairs on the margin, 

 third antennal joint very large, bright yellowish-red. Legs black. 



Male. — Front prominent, opaque, strongly sulcata medially, very 

 indistinctly punctulate, long black pilose. Face shining black, pollinose 

 on the sides and pilose on orbital margin below ; below the anteniice 

 deeply concave to the tip of the tubercle, thence gently concave to the 

 epistoma. Tubercle projecting somewhat beyond the base of the third 

 antennal joint, round. Cheeks shining, sparsely whitish pilose. Ocellar 

 area black pilose. Eyes metallic. First antennal joint black, second 

 dark reddish-brown, third bright yellowish-red, very large, subquadrate, 

 with the lower outer corner rounded, upper corner obtusely pointed. 

 Arista basal, black, incrassate, densely plumose. Dorsum of the thorax 

 very lightly punctate, shining greenish-black, abundantly whitish pilose 

 (viewed from in front) mixed with black in the middle, longer posteriorly. 

 Scutellum lightly punctate, abundant long black pilose, with a few light 

 hairs intermixed. Pleura abundant long whitish pilose. Abdomen 

 with the sides almost parallel, short sparse yellowish pilose, more 

 abundant on the sides, where it is intermixed with a few black hairs. 

 First segment entirely opaque, second and third except on the lateral 

 margins, fourth entirely, bright shining greenish. Legs black, all the 

 knees reddish ; pile in most reflections black ; on the under side of all the 

 tarsi and the anterior tibiai, golden in some reflections. Wings hyaline, 

 veins dark brown, apical cross-vein almost straight, without stump. 

 Length, y^^ mm. Al., 7 mm.; i 4-5 mm. wide. 



Female. — Differs from the male in having the front shining and 

 lighter pilose, the dorsum shorter pilose, the abdomen entirely shining, 

 and the third antennal joint much larger ; in this sex it is enormous — 

 one and one-half times as large as in the male, but of the same shape. 



Three specimens ; Moscow, Idaho ; Prof. J. M. Aldrich. 



This species is closely allied to C. Wmistoni, but is specifically 

 quite distinct in the larger size and different shape of the third antennal 

 joint, in the fact that the arista is densely plumose, while in that species 

 it is loosely so, and that in the male the abdomen is largely opaque. 



