WHITEFISH  , a collective name applied in different countries to very different kinds of

freshwater fishes . The numerous European species of the Cyprinoid genus Leuciscus are frequently comprised under the name of " Whitefish," but the term is employed here for the various species of the Salmonoid genus Coregonus . The Coregonus group are somewhat herring-shaped, silvery salmonids with small, toothless or feebly toothed mouth, and rather large scales . They are distributed over Europe, Asia and North America, some species living in the sea, but most inhabiting clear lakes . The highly esteemed " lavaret " of Savoy, the " felchen," " kilch," " gangfisch," " palee," " gravenche," " fera " or Switzerland and southern Germany, the " sik " of Sweden, belong to this genus, which is represented in British and Irish waters by the houting (C. oxyrhynchus), occasionally found in the North Sea, the gwyniad or pawan (C. clupeoides) of Loch Lomond, Haweswater, Ullswater and Bala, the vendace (C. vandesius) of Lochmaben, and its newly described ally (C. gracilior) from Derwentwater and Bassenthwaite lakes .in Cumberland . About eight species are distinguished from the northern parts of 'North America . The Coregonus are mostly of small size, few of them attaining a length of 18 in . Secondary nuptial sexual characters are by no means so well marked as in Salmo, but pearl-like excrescences may appear on the scales during the breeding season, and are more prominent in males than in females .