280 
THYMALLUS. 
With the structure of the jaws like the Trouts, the mouth has a 
limited opening; teeth very fine. Scales on the body large. Dorsal 
fin rather long, wide. Seven or eight rays in the gill-membrane. The 
small square mouth, coupled with the high dorsal fin, will distinguish 
this genus. 
GRAYLING. 
Grayling, 
Thy mall ns, Uniber, 
Coregcniis thymallus, 
,1 ‘I 
Thymallus vulgaris, 
» •• 
JoKSTON; pi. 26, f. 3. 
WiLLOUGUBY; p. 187, table N. 8. 
Lissjeus. Bloch ; pi. 24. 
Fleming; Br. Animals, p. 181. 
CuviEE. Jenyns; Manual, p. 430. 
Yaxeell; Br. Fishes, vol. ii, p. 136. 
It is to be observed that Rondeletius makes the Umira 
Jlumatilis and Thymus to be different species; but what he 
says of either of them may apply to our Grayling, although 
his figure of the Thymus is represented too deep, unless, 
perhaps, when the fish is heavy with spawn. Gesner believes 
the Umbra to be our Grayling; but a fish of the same name 
mentioned by Columella belongs to the sea, and is our Scimna 
or Maigre, of which the word Umbra is a translation. 
It is not the least remarkable portion of the history of the 
Grayling, that its distribution among the rivers of our country 
is as irregular as it is limited; so that while it is abundant 
in some places, especially in the north and east of England, 
in others, perhaps not far removed, and also in the south 
and west, it is unknown; nor has it been discovered in any 
part of Scotland and Ireland, although there are situations in 
these portions of the United Kingdom which appear to be 
equally Avell adapted to its habits. Circumstances of this 
nature have given rise to the supposition that the Grayling, 
