504 NORTH AMERICAN FAUNA. [no. 27. 



Moxostoma lesueuri (Richardson). Gray Sucker. 



Under this name I include a few notes on a large-scaled sucker, 

 usually called in the north gray sucker. It is equally common with 

 the preceding species in many localities, and has nearly or quite as 

 extensive a range. It is a common fish in Great Slave Lake and the 

 Mackenzie. Pere Giroux informed me that it appears in numbers at 

 Arctic Red River about the first week in June, but practically dis- 

 appears after remaining abundant about three weeks. A specimen 

 which he gave me measured: Total length, 18 inches; depth, 2| 

 inches. It was among those subsequently lost. 



Couesius plumbeus (Agassiz). Northern Shiner. 



Previous to our explorations this species was unknown as an in- 

 habitant of the Mackenzie Valley. In August, 1903, while following 

 the canoe route between Great Slave and Great Bear lakes, I observed 

 these small ' shiners' in a number of places. While encamped on Lake 

 St. Croix I succeeded after a good deal of effort (for I was not pro- 

 vided with small hooks) in catching two of these fishes, using small 

 spiders for bait. These specimens have been identified and recently 

 recorded by Evermann and Goldsborough. 



This fish probably has an extensive distribution in the Mackenzie 

 Valley. In June, 1901, I saw a number of small fishes of precisely 

 similar appearance and probably of the same species as my Lake St. 

 Croix specimens, in a small pond near the mouth of North Nahanni 

 River. I have seen similar minnows in a number of other localities. 



Platygobio gracilis (Richardson). Flat -headed Minnow. 



This peculiar fish was first described by Richardson from the Sas- 

 katchewan at Carlton House, but apparently was not recorded from 

 the Mackenzie Valley until 1907, when Evermann and Goldsborough 

 recorded specimens taken by myself in 1901 at Grand Rapid, Atha- 

 baska River; and Fort Simpson and Fort Good Hope, Mackenzie 

 River. Mr. Evermann, however, tells me that in working over the 

 specimens in the National Museum he discovered an example which 

 was taken by Kennicott at Fort Simpson, but which had been pre- 

 viously overlooked. 



I found the flat-headed minnow to be an exceedingly abundant fish 

 throughout the entire length of the Athabaska and Mackenzie rivers, 

 from Athabaska Landing northward. These muddy rivers seem to 

 be its delight, and I have never seen it in clear water. It congregates 

 in the eddies close to the bank and swims slowly along with the top 

 of its head nearly flush with the surface. It is readily caught with a 

 baited hook, and its capture is a favorite amusement with the Indian 



Proc. Biol. Soc. Wash., XX, p. 9S, 1907. 



