64 c Canadian Arctic Expedition, 1913-18 



Johansen in his notes sketches one of the puparia so curved that the cephalic 

 extermity extends to or almost to the surface, which is assumably the position 

 immediately before the emergence of the imago, but all the empty puparia in the 

 collection are nearly straight. (Rearing 78). 



The puparium of Hydrophoria, an aquatic genus, is not conspicuously 

 dissimilar from those of terrestrial Anthomyiidae, showing no caudal modification 

 or specialization such as is shown in the present genus. 



The imago bears a resemblance to some species of Aricia, but differs in 

 having the facalia hairy for a greater length above the vibrissas, the third antennal 

 joint much shorter, the under scale of calyptrae much narrower, and the fore tarsi 

 without spines on ventral surfaces. The female resembles Aricia also, but has, 

 in addition to the differences present in the males, the orbits much more hairy, 

 the upper portion with a double series of long, hair-like bristles, the outer series 

 directed out over the eyes. 



In some respects the genus resembles Trichophthicus, especially in the 

 character of the fore tarsi, but the tibiae in Trichophthicus are strongly spinose, 

 the third antennal joint is much longer than the second, and the hind coxae 

 have hairs above at apex. 



Aricia Robineau-Desvoidy. 



I refer one species in this collection to this genus, although the male differs 

 in many respects from the genotype, and in general habitus resembles Trich- 

 opticus Rondani. From Trichopticus the present species differs in having the 

 posterior coxae bare above at apices. 



Aricia borealis, n. sp. 



Male. Black, shining. Interfrontalia opaque black, orbits silvery pilose. 

 Thorax very slightly greyish priunescent, not distinctly vittate. Abdomen 

 when viewed from behind, with brownish pruinescence and a black median 

 longitudinal stripe. Legs black. Wings slightly greyish, fuscous at bases. 

 Squamae yellow. Halteres black. 



Eyes bare, separated by about one-seventh the head-width; orbits linear 

 above, not one-third as wide as interfrontalia at its narrowest point; antennae 

 short, third joint 1-5 as long as second; arista almost entirely nude; cheek with 

 many long hairs; vibrissa poorly differentiated; orbit in profile projecting 

 beyond eye farther than width of third antennal joint. Presutural acrostichals 

 irregularly four-rowed; postsutural dorso-centrals four in number; prealar 

 bristle weak but distinguishable; sternopleura with long hairs and two strong 

 bristles; pteropleura and hypopleura bare. Abdomen subcylindrical, slightly 

 tapering to apex; fifth sternite with small rounded central excavation in posterior 

 margin. Fore tibia with three to four bristles in a single series on^ apical third of 

 postero- ventral surface; mid femora slightly attenuated apically, with two to 

 three long bristles at base on anterior side; mid tibia with almost the entire 

 length of the postero-dorsal surface with short bristles, two to three on posterior 

 surface, and three to four on postero-ventral surface beyond middle; hind 

 femora with bristles on entire length of antero-ventral surface, the postero- 

 vental surface unarmed; hind tibia slightly curved, the apex on ventral side very 

 distinctly produced, anterior and posterior surfaces with short, regular, setulose 

 hairs, those on postero-dorsal surface longest (PI. IX, fig. 27) ; hind tarsi with 

 a pair of bristles at base of first joint noticeably longer than the others. Last 

 sections of third and fourth veins parallel; outer cross-vein slightly curved, last 

 section of fourth vein 2-5 as long as preceding section. 



Length, 7 • 5 mm. 



Type locality: Bernard harbour, Dolphin and Union, strait, Northwest 

 Territories, July, 1916 (F. Johansen). 



