84 c Canadian Arctic Expedition, 1913-18 



longer bristles on posterior margins of segments; hypopygium of moderate size, 

 subglobose. Legs with a few bristles but with numerous short setulose hairs; 

 fore femora with long bristles on postero-dorsal and postero-ventral surfaces; 

 mid femur with at least one moderately strong bristle on anterior surface at 

 middle; mid and hind tibiae with preapical dorsal bristle, fore pair not visible. 

 Inner cross-vein before extreme apex of first vein and slightly beyond middle 

 of discal cell; outer cross-vein straight, at more than half its own length from 

 end of fifth; last section of fourth nearly 1 -5 as long as preceding section; costal 

 spines very little longer than diameter of costal vein. 



Length, 4 mm. 



Type locality: Nome, Alaska, August 24 and 25, 1916 (F. Johansen). 



PIOPHILID^). 



The larvse of all species of this family known to me feed in carrion, or on 

 preserved meats, cheese, etc. I have found some species in numbers on dead 

 animals, especially on the seashore and on the banks of rivers. There is only 

 one specimen in the present collection, which is herein described as new. 



Piophila borealis, n. sp. 



Male. — Glossy black. 



Head black, interfrontalia, lower part of orbits, face, cheeks, and palpi 

 reddish yellow. Thorax black, humeri, lateral portions of scutellum, and 

 posterior lateral angles of mesonotum translucent red; propleura grey pruinose. 

 Abdomen black. Legs black, trochanters, extreme apices of femora, bases 

 (broadly) and apices (narrowly) of all tibiae, basal four joints. of mid, and three 

 joints of hind, tarsi reddish yellow. Wings clear, veins yellow. Halteres 

 yellow. 



Frons plain, with weak setulae proximad of triangle; anterior orbital bristle 

 very small; central postvertical pair of bristles twice as long and strong as 

 laterals; vibrissa strong; cheek almost as high as eye. Thorax smooth, rather 

 densely covered with short dark hairs; scutellum subtriangular, convex in centre 

 of disc; apical bristles distinctly longer than laterals; propleural bristles of 

 moderate length. Abdomen broad, the surface granulose and armed with 

 rather closely placed short setulose hairs; hypopygium small. Legs normal 

 both in strength and armature. Inner cross-vein slightly beyond apex of first; 

 sections of fourth vein 6:5:7 from base to apex. 



Length, 3 mm. 



Type locality: West of Konganevik, Camden bay, Alaska, July 4, 1914 

 (F. Johansen). 



This species differs in the colour of the humeri and scutellum from any 

 described in the recent paper on the family by Melander and Spuleri. 



EPHYDRID^. 



The members of this family are found in the vicinity of water, the larvae 

 being almost without exception aquatic. 



There is only one species in this collection. 



Scatella brunnipennis Malloch. 



I described this species in the paper on Pribilof Island Diptera previously 

 referred to, but which has not yet appeared in print. 



Localities: Demarcation point, Alaska, and Collinson point, Alaska, May 

 16, and June 20, 1914; Collinson point, Alaska, September, 22, 1913; Bernard 

 harbour, Northwest Territories, July, 1915 (F. Johansen). 



i Bull. 143 Wash. Agr. Exper. Station, 1917. 



