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, Jonston ; pi. 26, f. 3. 



Thymallus, Umber, Willoughby; p. 187, table N. 8. 



Coregonus thymallus, Linnjeus. Bloch ; pi. 24. 



" " Fleming; Br. Animals, p. 181. 



Thymallus vulgaris, Cuvieb. Jenyns; Manual, p. 430. 



" " Yakrell; Br. Fishes, vol. ii, p. 136. 



It is to be observed that Rondeletius makes the Umbra 

 Jluviatilis 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 Scisena 

 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 well adapted to its habits. Circumstances of this 

 nature have given rise to the supposition that the Grayling, 



