50 c Canadian Arctic Expedition, 1913-18 



x 



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 brevipennis 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 pcstero-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 

 arc 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.) 



Iluilrophorus notatus Zetterstedt, Ins. Lapp., sp. 701, 1838. 

 Hydrophorus spinimanus, Zetterstedt, Dipt. Scand., vol. 2, p. 445, 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 arc 

 predaceous and run with great facility upon water surfaces. The genus is 



northern in its distribution. 



Hydrophorus innotatus Loew. 



Hydrophorus In.nolaln,* Lo<;w, Mon. X. Am. Dipt., vol.2, p. 212, 18(11. 



Represented in the collection by three specimens: two males, Bernard 

 harbour, Northwest Territories, June, 1915; and one female, Collinson point, 

 Alaska, -June 20. 11) 1-1 (F. .lohansen). 



Originally described from Sitka, Alaska. I have seen examples from 

 Pribilof islands. 



Hydrophorus signiferus Coquillett. 



Hydrophorus .s/V/////V/-//.s roqnillrtt. The fur seals and fur seal islands of the north Pacific 

 Ocean, veil. K p. 344, 1S'.!. 



Mdentily ag 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. 



