74 c Canadian Arctic Expedition, 1913-18 



Locality: Bernard harbour, Dolphin and Union strait, Northwest Territories, 

 August 1-7, 1915, and July, 1916 (F. Johansen). 



Phorbia, sp. 3. 



One male in very poof condition. Resembles brevitarsata in armature 

 of the legs, but differs in having the abdomen depressed, and the hind tarsi' 

 about as long as the tibia. 



Locality: On sandy beach, Bernard harbour, Dolphin and Union strait, 

 Northwest Territories, July 19, 1915 (F. Johansen). 



Phorbia, spp. 



Five specimens belonging to this genus are in such poor condition that 

 I cannot satisfactorily assign them to any of the preceding species or to any 

 known to me. 



Locahty: Herschel island, Yukon Territory, July 29, 1916, one female; 

 Bernard harbour. Northwest Territories, July 10, 1915, one male, one female; 

 same locality, June 18, 1915, one female; Collinson point, Alaska, June 20, 

 1914 (F. Johansen). 



Pegomyia Robineau-Desvoidy. 



This genus as at present constituted contains species which are very dissimilar 

 in habitus, and my knowledge of the larval habits of a number of the species 

 leads me to consider certain that such species as unicolor Stein, affinis Stein, 

 and bicolor Wiedemann are not congeneric. The first-named I have reared 

 from mushrooms, and the larva resembles much more closely that of Anthomyia 

 pluvialis Linne than that of bicolor, which is a leaf-miner. The larvae of 

 affinis are found in burrows of rodents and in caves or holes in the ground wMch 

 mammals or birds frequent and are essentially scavengers; their structure 

 is unknown to me. Both species in the present collection are more closely 

 related to unicolor than to bicolor and may have the same larval habits. 



Pegomyia flavipes (Fallen.) 



Anthomyia flavipes Fallen. Dipt. Suec, Muse, p. 90, sp. 125, 1820. 

 Anthomyia pulchripes Loew. Zeitschr. f. Ges.' Natiirwiss, lt)4. 1857. 

 Pegomyia flavipes (Fallen) Stein, Wien Ent. Zeitg., vol. 25, p. 69, 1906. 



This species has the general habitus of unicolor Stein, but is considerably 

 darker in colour and is separable from its congeners by the remarkably long 

 bristles on the antero-ventral surface of the hind femora, the longest one being 

 at least three times as long as the diameter of the femora where it is situated. 

 The lower bristle on the postero-dorsal surface of the hind tibia is about half 

 as long as the tibia.' 



One male specimen in verv poor condition, Nome, Alaska, August 21, 

 1916 (F. Johansen). 



Pegomyia albimargo Pandell. 



Pegomyia albimargo PandeU, Rev. Ent. France, vol. 20, p. 296, 1901. 



Phorbia obscura Meade (nee Maequart). Ent. Month. Mag., vol. 19, p. 216, 1883. 



This species is one of the smallest and most variable in colour in the group. 

 Sometimes the whole insect, including the legs, is black, but commonly the 

 abdomen and at least the tibiae are reddish, or translucent. The thorax is always" 

 black and in front is marked with four short vittse, between which the- dorsum 

 is conspicuously white pruinescent. The black antennae and palpi serve to 

 distinguish the species from vittigera Zetterstedt, which it most closely resem- 

 bles in the chaetotaxy of the legs. 



