THE ARCTIC GRAYLING. 
THE GRAYLINGS. 
Effigiens oculis celeri umbra natatu. 
Ausonius ; The Moselle. 
} I v WO species of the genus Thymallus occur in North America, one, the 
Arctic Grayling T. signifer , the other the Michigan Grayling T. 
tricolor , the diagnostic characters of which are thus defined by Bean : 
SPECIES OF GRAYLING. 
A. Gill-rakers 22 ; pyloric cceca 19 ; maxilla 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 1819, and called Thymallus signifer, by 
Sir John Richardson, who thus describes its discovery: 
“ This very beautiful fish 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 I 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. 
