The Diptera collected by the Canadian Expedition, 1913-1918. 



(Excluding the Tipulidse and Culicidse.) 



By J. K. MALLOCH. 



INTRODUCTION. 



This paper deals with the Diptera collected by the Canadian Arctic Expedi- 

 tion 1913-Ki, and belonging to the following families: Sciaridae, Chironomidae, 

 Simuliidse, Leptidae, Empididae, Dolichopodidae, Phoridae, Borboridae, Syrphidae, 

 Oestrida 1 . Tachinidse, Calliphoridae, Anthomyiidae, Scatophagidae, Helomyzidae, 

 Piophilida?, Ephydridse, and Chloropidae. The number of species in the paper 

 is ninety-three, representing fifty-five genera. 1 



Some of the genera and species included in this list are new to science, but 

 others are recorded for the first time from Arctic America, having been previously 

 known from the Arctic regions of the Old World. It is probable that many 

 of the forms are circumpolar in their distribution, but the difficulties attendant 

 upon their collection in the latitudes where they occur make it almost impossible 

 to obtain representative collections from many regions. 



( 'ollections of Diptera from the far north present characteristics that 

 are unmistakable to the eye of one who has previously studied material in other 

 Arctic collections, since in both the remarkably uniform dull colours and in the 

 genera comprising such collections they differ very strikingly from those of tem- 

 perate regions. The predominating body-colour is a deep black, relieved 

 occasionally with blue-black species such as the flesh-flies, and as a general rule 

 the flies are hairy or bristly. Most of the forms are scavengers, living on decay- 

 ing animal or vegetable matter, but a few are parasitic or predaceous. The 

 phytophagous forms are rare, and from the far north no Trypetidae are recorded, 

 tin- most northern locality for that family being the Pribilof islands. 



The work upon this collection was undertaken with the consent of Dr. 

 Stephen A. Forbes, Thief of the Division of Natural History Survey of Illinois. 



SCIARID^. 



The larvae of this family live in decaying vegetable matter, sometimes in 

 fungi, and occasionally in vegetation that has been attacked by other larvae. 



There are three species in this collection, none of which it is possible to 

 identify specifically on account of their being represented only by females, and 

 also owing to their defective condition. 



Sciara, sp. 1. 



This species has a peculiar wing venation which will enable some future 

 st udent In as-ociate t he specimen with others that may be subsequently obtained. 



The first vein ends in the cost a midway between the cross-vein and the 

 furcation of media, the latter originates about twice the distance of cross-vein 

 proximad of the latter, runs very close to the upper branch of cubitus to the 

 tork, the anterior branch then runs abruptly forward (towards costa) at almost 

 a right angle to lower branch, curves round when about one-third of the distance 

 to radius and runs to apex of wing, the cell it encloses being narrowed apically. 



7'///;r.s. The types of the new species described in this report are deposited in the National 

 <f Insects, < )tta\va. 



