78 c Canadian Arctic Expedition, 1913-18 . 



Frons about half the width of head, each orbit nearly half as wide as inter- 

 frontalia; lower supraorbital bristle directed forward, the upper two slightly 

 backward; antenna? large, third joint broad, its width over half that of eye, 

 apex not acute, entire length on inner side nearly four times that of second; 

 arista microscopically pubescent, second joint about one-fourth as long as 

 third, the latter swollen on its basal two-fifths; profile as in PL X, fig. 34; 

 hairs of lower part of occiput mostly white. Dorsum of thorax with two-f- 

 three dorso-centrals; acrostichals irregularly two-rowed before suture; discal 

 setulse sparse and long; scutellum with four long bristles and a number of long 

 setulose discal hairs; sternopleura with two long posterior bristles placed verti- 

 cally and many long strong hairs; prothoracic and stigmatal bristles strong. 

 Abdomen with numerous long hairs, those on posterior margins strong but not 

 macrochaetse. Legs normal; fore tibia with two antero-dorsal, two postero- 

 clorsal, and one posterior bristle; mid tibia with one ventral, two antero-dorsal, 

 two postero-dorsal, and one posterior bristles; hind tibia with one large and 

 one to two small antero-ventral, three antero-dorsal, and four to five postero- 

 dorsal bristles. Costa with fine setulse and more widely spaced spinules; outer 

 cross vein straight, situated at nearly its own length from end of fifth vein, 

 last section of fourth vein nearly twice as long as preceding section. 



Length, 5-5 mm. 



Type locality: Bernard harbour and cape Krusenstern, Dolphin and Union 

 strait, Northwest Territories, July 3, 1916 (F. Johansen). 



I have seen a specimen which I consider belongs to Gonatherus planiceps 

 Fallen, the genotype, in another collection from Alaska. From atricornis it 

 differs in having the palpi entirely whitish, the legs paler, the wings conspicuously 

 brown along costa and on each side of longitudinal and cross-veins, and in being 

 much less strongly bristled, the acrostichals in front of suture being less numerous 

 and weaker. The two species are very closely related but in my opinion readily 

 separable by the characters indicated herein. 



Cordylurella, n. gen. 

 Generic Characters. 



Female. — Head, viewed from above, subspherical, slightly flattened 

 posteriorly; frons one-third or more than one-third the head-width; orbits 

 differentiated; the bristles well developed, similar to those of Cordylura; antennae 

 slightly shorter than face, third joint rounded apically, arista pubescent; palpi 

 without strong apical bristle. Thoracic chactotaxy as in Cordylura. First 

 wing-vein bare; sixth not reaching margin of wing. Legs similar to those of 

 Cordylura. 



Genotype: Cordylura nebulosa Coquillett. 



There is a male specimen of a species which I refer to this genus in the 

 collection. I can not identify it as any previously described species, and describe 

 it herewith as new. 



Cordylurella subvittata, n. sp. 



Male. — Black, glossy. Head yellow; occiput, ocellar triangle, and greater 

 portion of frontal orbits glossy black, the orbits and triangle slightly pollinose; 

 face and cheeks with distinct white pruinescence; antennas yellow; arista black; 

 palpi yellow; proboscis yellow at base, becoming brown at apex. Thorax glossy 

 black, lateral margins, a narrow line along course of dorso-centrals, and a broad 

 central vitta covered with very short grey pile, giving the dorsum a subvittate 

 appearance. Abdomen glossy black; surface with long but not dense yellow 

 hairs, bristles on penultimate dorsal segment black; hypopygial forceps yellow 

 except at base. Lea;* yellow, mid and hind coxse brown. Wings clear, veins 

 brown. Halteres brown. 



