COREGONUS OXYRHYNCHUS. 837 



scales on the sides of the body develop tubercles, like those o£ Cyprinoid fishes. 

 Individuals of the same size herd together in schools. The species are all 

 valued for food, and most are esteemed for their delicate flavour ; they are as 

 numerous as in the genus Salmo. The geographical range is limited in some 

 types^ while other types are as widely distributed as some kinds of Salmon. 

 The species are often difficult to separate, and are best distinguished, according 

 to Dr. Giinther, by the shape of the snout, its relative length, the development 

 of the maxillary bone, form of the supplementary maxillary bone, length of 

 the mandible, height of body and tail, position of the dorsal fin, and number 

 of scales and vertebrae ; but these characters often define species on small 

 differences. 



Most species have the upper jaw the longer, though many have the lower 

 jaw longer than the snout, and differences in the length of snout are easily 

 recognised, and we have followed Dr. Giinther in grouping the species by 

 this characteristic. 



(1.) Species irith the upper jaw prolouped. 



Coregonus oxyrhynchus (Linn/eus). 



D. 14, A. 14—15. Scales : lat. line 75—81, transverse — - 



12. 



This fish frequents the coasts, and enters the fresh waters of Belgium, 

 Holland, Germany, Denmark, and Sweden. It is known in Belgium as 

 Ilautiii, is common in Antwerp, and sent thence to Paris, where it is sold in 

 the fish-markets as L'until . In Holland it is plentiful, known to fishermen as 

 the 7/o/?////.{/, and also supplies the French markets. In Germany it is popularly 

 known as Selinapel. It is very rare in France, but is said sometimes to be 

 caught in the Doubs. It ascends the Hhine as far as Strassburg, is found in the 

 Maas and Scheldt, Weser, Elbe, and the rivers flowing into the North Sea and 

 Baltic. It thrives as well in the sea as in lakes and rivers. Mr. Day records 

 it as a British species from Lincolnshire, Chichester, and the Medway, taken 

 with Smelts. 



C. oxyrhynchus is easily distinguished from all other species by its long 

 conical fleshy snout. The head is compressed and small. It is two-ninths or 

 one-fifth of the total length, exclusive of the caudal fin, and the height of the 

 body slightly exceeds the length of the head. The maxillary bone extends 

 below the fatty eyelid, and is more than one-quarter of the length of the head. 

 The mouth is at the lower and hinder extremity of the soft black snout. 

 Behind the head the back is moderately curved, but enough to give the aspect 

 of a high shoulder. The scales are more circular than in other species, with 

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