26 BRITISH FRESHWATER FISHES 



present on the shaft of that bone, at least in 

 the young — Salmon and Trout. 



Vomerine teeth restricted to a group on 

 the head of the bone, behind which there is 

 a boat-shaped depression — Char. 

 II. Mouth small, the maxillary short; scales of 

 moderate size. 



Teeth minute or absent ; dorsal fin with 

 lo to 1 6 rays — White-fish. 



Teeth small; dorsal fin with i8 to 24 

 rays — Grayling. 



The Salmon {Salmo salar) is an inhabitant of the 

 North Atlantic, ranging northwards to Hudson Bay, 

 Greenland, Iceland, and Northern Europe, and south- 

 wards to Cape Cod and the Bay of Biscay, and 

 entering all suitable rivers to spawn. In the British 

 Isles it is most abundant in Scotland and Ireland ; 

 Wales and the West of England come next, but the 

 pollution of the Thames and some other English 

 rivers renders them uninhabitable for this species at 

 the present day ; in former times the Thames was 

 a noted Salmon river, but even in i 841 Yarrell wrote, 

 " A Thames Salmon is a prize to a fisherman, which 

 like other prizes, occurs but seldom. The last Thames 

 Salmon I have a note of was taken in June 1833." 



The adult fish has a slender fusiform body and 

 a rather small conical head ; it is silvery, bluish grey 

 above and white below, with scattered blackish spots 

 present only above the lateral line, except some- 

 times anteriorly ; the dorsal, caudal, and pectoral 

 fins are bluish black, the first named often with 

 some blackish spots near the base, whilst the pelvic 

 and anal fins are white. Of characters which dis- 



