THE ARCTIC GRAYLING. 



THE GRAYLINGS. 



Effigiens oculis celeri umbra natatu. 



Ausoxius ; The Moselle. 



HP WO species of the genus Thymallus occur in North America, one. the 

 Arctic Grayling T. signifcr, the other the Michigan Grayling T. 

 tricolor, the diagnostic characters of which are thus denned by Bean : 



SPECIES OF GRAYLING. 



A . Gill-rakers 22 ; pyloric cceca 19 ; maxilla y 3 head ; mandible equal to anal base ; eye nearly equal to inter- 

 orbital space ; dorsal when laid back not reaching adipose fin. T. TRICOLOR. 



aa. Gill-rakers 18 ; pyloric coeca 18 ; 3-10 head ; mandible much shorter than anal base ; eye much less than 

 interorbital space ; dorsal when laid back reaching end of adipose fin. T. SIGNIFER. 



The Arctic Grayling was first found by Capt. John Franklin's expedi- 

 tion toward the North Pole, in 1S19, and called Thymallus signifer, by 

 Sir John Richardson, who thus describes its discovery: 



" This very beautiful fislf abounds in the rocky streams that flow through 

 the primitive country lying north of the sixty-second parallel between 

 Mackenzie's River and the Welcome. Its highly appropriate Esquimaux 

 name (' Hewlook-Powak,') denoting ' wing-like,' alludes to its magnificent 

 dorsal, and it was in reference to the same feature that 1 bestow upon it the 

 specific appellation of Signifer or the 'standard-bearer.' intending also to 

 advert to the rank of my companion, Captain Back, then a midshipman, 

 who took the first specimen that we sawwith the artificial fly. It is found 

 only in clear waters, and seems to delight in the most rapid parts of the 

 mountain streams." As is implied in these remarks, this species is re- 

 markable for its immense dorsal fin, which is nearly twice as high as the 

 body of the fish. 



