50 c Canadian Arctic Expedition, 1913-18 
eight bristles in two irregular series. Curve of fourth vein distinct but not 
abrupt; apices of third and fourth veins subparallel; costa not noticeably swollen 
at apex of first vein. 
Length, 5-25 mm. 
Type locality: Bernard harbour, Dolphin and Union strait, Northwest 
Territories, July 10, 1916 (F. Johansen). 
This species is most closely allied to hrevipennis Meigen, but differs in 
having the hind femora without long pale hairs on ventral surface. 
Dolichopus, sp. 
A female in collection which is in very poor condition may belong to dasyops. 
It agrees very well in colour with the male above described. The wing has a 
knot-like swelling on the costa at end of first vein. The hind tibia has on basal 
half of the postero-dorsal surface a distinct groove or channel which is evanescent 
at its extremities, and at apex on dorsal surface another short groove; the bristles 
on hind tibia are as follows: five almost exactly on the dorsal surface, six to 
seven on antero-dorsal surface, and four to five on antero-ventral surface which 
are very weak but increase in strength to apex. 
Locality: Nome, Alaska, August 21, 1916 (F. Johansen). 
Scellus Loew. 
The flies of this genus are predaceous. There are six described North 
American species. The single species in the present collection was originally 
described from northern Europe and was recorded from Fort Resolution, Hudson 
Bay territory, by Loew. There are no subsequent records for North America. 
Scellus spinimanus (Zetterstedt.) 
Hydrophorus notatus Zetterstedt, Ins. Lapp., sp. 701, 1838. 
Hydrophorus spinimanus, Zetterstedt, Dipt. Scand., yol. 2, p. 44.5, 1843. 
Two males and ten females, Bernard harbour. Northwest Territories, August 
26, 1915; two females, Cockburn point, Arctic coast. Northwest Territories, 
September 7, 1914 (F. Johansen). 
Hydrophorus Fallen. 
There are three species of this genus in the collection. The imagines are 
predaceous and run with great facility upon water surfaces. The genus is 
northern in its distribution. 
Hydrophorus innotatus Loew. 
Hydrophones innotatus Loew, Mon. N. Am. Dipt., vol. 2, p. 212, 1864. 
Represented in the collection by three specimens: two males, Bernard 
harbour. Northwest Territories, June, 1915; and one female, Collinson point, 
Alaska, June 20, 1914 (F. Johansen). 
Originall}^ described from Sitka, Alaska. I have seen examples from 
Pribilof islands. 
Hydrophorus signiferus Coquillett. 
Hydrophorus signiferus Coquillett. The fur seals and fur seal islands of the north Pacific 
Ocean, vol. 4, p. 344, 1899. 
I identify as this species twelve specimens, representing both sexes. 
The species was originally described from a female specimen, and several 
important characters are omitted. I, therefore, redescribe the species from 
both sexes. 
