The Diptera collected by the Canadian Expedition, 1913-1918. 
(Excluding the Tipulidse and Culicidse.) 
By J. R. Malloch. 
Introduction. 
This paper deals with the Diptera collected by the Canadian Arctic Expedi- 
tion 1913-16, and belonging to the following families: Sciaridse, Chironomidae, 
Simuliidse, Leptidse, Empididse, Dolichopodidse, Phoridse, Borboridse, Syrphidse, 
Oestridse, Tachinidse, Calliphoridse, Anthomyiidse, Scatophagidae, Helomyzidse, 
Piophilidse, Ephydridse, and Chloropidse. The number of species in the paper 
is ninety-three, representing fifty-five genera.^ 
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 
kno^\^l 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. 
Collections 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/ule 
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 Trypetidse are recorded, 
the 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, Chief of the Division of Natural History Survey of Ilhnois. 
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 
student to associate the specimen with others that may be subsequently obtained. 
The first vein ends in the costa 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 
fork, 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. 
. . • 
1 Types. The types of the new species described in this report are deposited in the National 
Collection of Insects, Ottawa. 
