66 c Canadian Arctic Expedition, 1913-18 



This species differs from any I have seen from North America, but owing 

 to the very close resemblance between species of this genus and, the poor state 

 of preservation of the specimen I do not consider it advisable to give it a name. 



Limnophora, sp. 2. 



A female taken on Herschel island, Yukon Territory, July 29, 1916 (F. 

 Johtosen), differs from the foregoing in having four pairs of postsutural dorso- 

 centrals, the acrostichals two-rowed, dorsum of thorax distinctly trivittate, 

 mid tibia with two antero-dorsal and three postero-dorsal bristles, hind tibia 

 with one antero-ventral, two antero-dorsal, and tw9 postero-dorsal bristles, 

 and the last section of fourth vein comparatively longer. 



Length, 4-75 mm. 



Pogonomyia Rondani. 



This genus has much in common with Trichopticus. In fact it is difficult 

 to separate the males of some species from those of Phaonia and Trichopticus. 

 The male of Pogonomyia nitens Stein was described as a Spilogaster, 'though 

 the author of that description recognized the female as a Pogonomyia — an 

 error which led me into describing the species in that genus under the name 

 Pogonomyia flavinervis. 



The characters which are of service in separating Pogonomyia from Tri- 

 chopticus are summarized as follows: — 



Male. — Eyes bare; prealar bristle long; fore tarsi short and with erect 

 short pile ventrally, the other tarsi spinDse ventrally; hind tibiae not curved, 

 with long and short bristles, without fine hairs; hind coxae bare above at apices. 



Female. — Differs from the male by the widely separated eyes; in other 

 respects similar, but with the lower supraorbital bristle directed forward and 

 with cruciate frontal bristles, characters which separate the genus from both 

 Phaonia and Aricia. 



There is one species in the collection, represented by one female, which 



> lacks the abdomen but is otherwise in good condition. The species resembles 



alpicola Rondani, a European species reported as occurring in North America. 



Pogonomyia quadrisetosa, n. sp. 



Female. — Black, shining. Orbits, ptilinum, and upper portion of cheeks 

 silvery pilose, face and lower portion of cheeks less distinctly silvery. Dorsum 

 of thorax slightly greyish brown pruinescent, with three poorly defined vittse 

 anteriorly. Abdomen missing. Legs black. Wings clear, veins yellowish ~ 

 except cpsta and base of first. Calyptrse whitish yellow. Halteres black. 



Cruciate frontal bristles strong; orbitals as in nitens Stein, except that 

 the weak hairs are more numerous; orbits in profile projecting as far beyond 

 eye as half the length of eye — much farther than in nitens: anterior angle of 

 cheeks protruding farther than frons at base of antennae; third antennal joint 

 slightly longer than second; arista microscopically pubescent; vibrissa very 

 little stronger than the other bristles, the latter covering a larger area than in 

 nitens; palpi much shorter than in nitens. Thorax with presutural acrostichals 

 weak, irregularly two or three-rowed ; postsutrual dorso-centrals four in niimber 

 rather weak; prescutellars as strong as dorso-centrals; pteropleura in type 

 with a long hair near middle. Fore tibia with three to four bristles on apical 

 half of postero- ventral surface; mid femora with a series of long bristles on 

 antero-ventral surface; mid tibia with three to four antero-ventral, four to 

 five antero-dorsal, five to six postero-dorsal bristles, and three to four 

 postero-ventral bristles; hind femora with a series of long bristles on antero- 

 ventral surface; hind tibia with five to seven long bristles on antero-ventral, 

 antero-dorsal, and postero-dorsal surfaces. Venation as in nitens. 



Length, 6-7 mm. 



