THE ANNALS 



AND 



MAGAZINE OF NATURAL EISTOllY. 



[EIGHTH SERIES.] 

 No. 9. SEPTEMBER 1908. 



XXIV. — A Preliminary Revision of the Irish Char, 

 By C. Tate Regan, M.A. 



Char are Salmonoid fishes of the genus Saheh'nus, whicli 

 differs from Sahno (salmon and trout) in having the vomerine 

 teeth present only as a group on the head of the bone, 

 which is raised and has a boat-shaped depression behind 

 it. Within the Arctic Circle and southwards to Iceland, 

 Hudson Bay, and the Kurile Islands migratory char are 

 found, which descend to the sea in the spring and towards 

 the winter re-enter the rivers to spawn. In these high lati- 

 tudes also many of the lakes are inhabited by permanently 

 freshwater colonies, which have found the conditions of life 

 favourable enough to induce them to abandon their habit 

 of migrating to the sea, whilst in some cases they have 

 become land-locked, so that they could not now migrate 

 even if they wished to. Some of these freshwater colonies 

 differ sufficiently from the migratory parent species to be 

 recognized as distinct species or races ; thus in Iceland the 

 non-migratory Salvelinus nivalis may be distinguished from 

 the migratory ;S'. alpinus. 



Further south all tiie char are non-migratory and are 

 principally restricted to deep cold lakes ; on the Continent of 

 Europe they are found in the lakes of Scandinavia, Switzer- 

 land, and the Tyrol, and in the British Isles they occur in 

 Scotland, the Lake District, North Wales, and Ireland. 



Ann. dc Mag. N. Hist. Ser. 8. Vol. ii. 16 



