156 MALACOP. ABDOM. SALMON FAMILY. 



several varieties, particularly one having a compara- 

 tively small head. The distinctive characters of 

 the Powan will be found in our Synopsis. 



(Sp. 137.) C, Pollan. The PoUan. Tliis species, 

 for a knowledge of which we are indebted to Mr. 

 Thompson of Belfast, * who has so successfully in- 

 vestigated the natural history of Ireland, is confined 

 to two or three of the Loughs of that country, and 

 occurs at times in prodigious abundance in Lough 

 Neagh. The Gwyniad and Powan are the only 

 other Coregoni of this country with which there is 

 any chance of confounding it, and this may be easily 

 avoided by attending to the following distinctive 

 marks. It differs from the former of these in the 

 snout not being produced ; the dorsal, anal, and cau- 

 dal fins considerably less ; the anal more distant 

 from the tail and having fewer rays ; and in the 

 third ray of the pectoral being longest, the first 

 being of greatest length in the Gwyniad. From 

 the Powan the most obvious difference is to be 

 found in the form of the mouth, which has a singu- 

 lar appearance owing to the great depth of the 

 upper lip and the length and breadth of the free 

 portions of the superior maxillary bones. This 

 character is well delineated in a comparative view 

 given in one of Mr. Yarrell's beautiful Vignettes, 

 Vol. IL p. 155. 



The habits of the Pollan do not seem to be dif- 

 ferent in any important respect from those of the 



* See Proceedings of Zool. Soe. for ] 835, p. 77. Magazine 

 of Zool. and Botany, vol. i. p. 247. 



