COKEGONUS ALBULA. , 349 



Dr. Gunther regards the species as made up of four varieties. 



There is, first, the variety a, distinguished as C. albula, which has fifty- 

 seven vertebrae, and is found in Lake Wener. The eye is as long as the snout, 

 fully one-fourth of the length of the head. The pectoral fin is as long as the head 

 without the snout. In males the height of the body is one-sixth of the total 

 length, exclusive of the caudal fin, or rather more. In females the height is 

 rather more than one-fifth of that length, while the length of the head varies 

 between one-fifth and two-ninths. It is adult at a length of six inches. 



The second variety, ft, called C. norwegica, has the eye rather shorter than 

 the snout, and a little less than one-quarter of the length of the head. The 

 pectoral fin is rather longer than the head without the snout, and is one-fifth of 

 the length of the fish without the caudal fin. The length of the head is two- 

 ninths, and the height of the body rather more than one-fifth, of the total 

 length, exclusive of the caudal fin. It is characteristic of Norway, is adult at 

 a length of seven inches, and also has fifty-seven vertebra. 



The third variety, 7, named C. tnarcenula, has the eye as long as the snout, 

 one-fourth of the length of the head. The pectoral fin is as long as the head 

 without the snout, but though these proportions resemble those of the variety 

 C. albula, the fin is two-elevenths of the length exclusive of the caudal, in 

 C. martenula, and two-thirteenths of that length in C. albula. The head is 

 one-fourth of the length, and the fish, without the caudal fin, is four and two- 

 third times as long as high. It is characteristic of North Germany, is adult 

 at a length of eight inches, though exceptionally reaching a length of a foot. 

 It has fifty- eight vertebrse. 



Dr. Giinther's fourth variety, S, named finnica, is known only from the 

 Gulf of Finland, where it is seven inches long. The head is two-ninths of the 

 total length without the caudal fin. 



Probably most species admit of being separated in this way into constituent 

 varieties, and we have given this classification as the best means of illustrating 

 the variability of the type under different geographical conditions. 



Except at spawning-time, which lasts a fortnight, it frequents deep water ; 

 but begins to travel in September and October, and, reaching shallow places, 

 drops about ten thousand large eggs, with noisy and lively movements, during 

 November and December. The female in Sweden is said to rub herself against 

 stones to get rid of the eggs. 



The flesh is sreatlv esteemed for food. It is eaten fresh, but is sometimes 



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smoked. It is known in Germany as Moranke or Kleine Marane. In Sweden 

 it is Sikldja, Smasik, or Sik. In Norway it is Lakesild, Skacld, or Wemme. 



