OF THE BRITISH ISLANDS. 165 



species of Corregoni are likewise gregarious Salmonidae, 

 restricted, however, like the Chars, with one exception (No. 

 1 50, which is both a marine and freshwater form), to our 

 larger upland lakes, and subject in a similar manner to 

 much local variation. In their size, shape, and their silvery 

 colouration they bear no inconsiderable resemblance to 

 the members of the Herring tribe, whence their popular name 

 of "Freshwater Herrings," but may be immediately 

 distinguished from such fish by the possession of a distinct 

 adipose dorsal fin. The four British species as recognised 

 by most authorities are the Houting, or sharp-snouted 

 Corregonus (Corregonus oxyrhynchus\ No. 150 ; the Guiniad 

 of Bala, and other North Wales lakes (C. clupeoides)* No. 

 151 ; the Vendace of Scotland (C. vendesius), No. 152 ; and 

 the Pollan and Powan of Ireland and Northumberland (C. 

 pollan), No. 153. The Grayling (Thymallus vulgaris), No. 

 154, is an example of the Salmon family, specially abun- 

 dant in the streams of Hampshire and other of our 

 southern counties. The Hebridal Smelt (Argentina 

 sphyrcena), No. 155, which closes the list of the British 

 Salmonidse, is a small northern marine type, not unfre- 

 quently taken among the islands to the North of Scotland, 

 and of which a preserved specimen will be found in the 

 series forming the Day Collection. 



FAMILY III. PIKES (Esocidce). 



Body covered with scales ; barbels none. Margin of upper 

 jaw formed mesially by the intermaxillary and laterally by 

 the maxillary bones ; no adipose fin, the single dorsal fin 

 developed towards the caudal extremity of the body. 



* Specimens of this type from Bala Lake, the gift of Sir Watkin 

 Williams Wynn, Bart., are on view in the Buckland Museum. 



