338 THE FRESH-WATER FISIIKS OF EUROl'K. 



denser concentric striae. The dorsal fin is in the middle of the back. The 

 pectoral is as long as the head, exclusive of the snout. 



The fish measures from sixteen to eighteen inches ; individuals of twenty 

 inches, with a weight of two pounds, are recorded in Denmark, while in Sweden 

 the weight may be eight to twelve pounds. 



It migrates and spawns at the end of October or beginning of November. 

 As in other species, rows of tubercles then appear on the scales of the male ; 

 two rows above the lateral line, and three below. After spawning, when 

 these growths have fallen off, the scales show longitudinal bands in both sexes. 



This species has fifty-eight vertebrae. 



Coregonus lloydii (GUNTHER). 



D. 14, A. 15. Scales : lat. line 90, transverse 



10. 



The Nabb-sik of Sweden was first regarded as a distinct species by Dr. 

 Giinther. It has thirty-nine vertebra? in the thorax, and twenty-three in the 

 tail. The length is about twenty-two inches. It is distinguished by smaller 

 scales, and longer and blunter snout from Coregonus oxyrhynchus, which it some- 

 what resembles. The height of the body is greater than the length of the head, 

 the former being one-fourth and the latter one-fifth of the length of the fish, 

 exclusive of the caudal fin. The upper jaw is produced into a short, fleshy 

 cone, and the profile of the snout makes a less acute angle than in C. oxyrhyn- 

 chns. The maxillary bone extends to the anterior border of the fatty eyelid, and 

 is, therefore, relatively shorter than in the former species. The supplementary 

 bone of the maxillary is long and narrow. Behind the head the back is 

 strongly arched. The pectoral fin is as long as the head, without the snout. 



In this species there are fully two hundred pyloric appendages to the in- 

 testine. 



It is found in Lake Wener and other localities. This species is very closely 

 allied to C. oxyrhynchus, of which it may prove to be a thick-nosed variety. 



(2.) Species with the snout obliquely truncated. 



Coregonus lavaretus (LINN^US). 



D. 14, A. 15. Scales : lat. line 90 94, transverse 



12. 



Many writers have described this fish, which is extremely variable, under 

 different names, such as C. marana, C.fera, and we owe the definition of cha- 

 racters which establish its geographical range, as indeed is the case with the 



