1 1. COHK(J0NUS. 



Coregonus lapponicus. 



181 



PPCoregonus sikus, Cuv.-Si' Val. xxi. p. 500. 

 B. 9. D. 15. A. 16. L. lat. 94-100. L. transv. 9/11. 



The height of the body is one-fourth of the total length (without 

 caudal), the length of the head one-fifth or rather more than one- 

 fifth. The diameter of the eye is one-fifth of the length of the head, 

 and two-thirds of that of the snout. Head small, moderately high ; 

 snout obliquely truncated, with the upper jaw projecting beyond 

 the lower. Interorbital space rather convex, its width being equal 

 to once and a third the diameter of the eye. The maxillary is short, 

 extending to below the anterior portion of the adipose eyelid, and its 

 length is contained four times and one-half or four times and one- 

 third in that of the head. The supplementrj^ bone of the maxillary 

 is broad, short, and subsemicircular. The length of the mandible 

 is less than the least depth of the tail. Back ascending from behind 

 the head in a strong curve. The origin of the dorsal fin is nearer to 

 the occiput than to the adipose fin. Pectoral longer than the head 

 without snout. 



Lapland. 



a-h. 16 inches long. From Mr. Wheelwright's Collection. 

 c, d. Several half-grown specimens, not in good state. Munio Biver. 

 From Mr. Wheelwright's Collection. 



This species is closely allied to C. lavarefus, but distinguished by 

 considerably smaller and shorter mandibles. 



The description of C. sikus given by Valenciennes is so insufficient, 

 that nothing but the locality leads me to suppose that this fish may 

 be identical with C. lapponicus. 



