304 



NORTHERN ZOOLOGY. 











Dimensions. 













Inches. 



Lines. 





Indies. 



Lines 



Lengt 



i from 



end of snout to tips of cauilul 



19 



6 



Breadth of nape 



. 1 



10 



» 



» 



end of central rays . 



18 



2 



Length of pectorals 



3 







V 



» 



end of scales on ditto . 



. 10 



7 



Height of dorsal 



. 3 







» 



» 



end of anal 



14 



3 



Length of its attachment 



3 







i> 



;> 



anus 



13 



tl 



„ ventrals 



. 2 



4 



?> 



» 



ventrals 



9 











6 



?» 



>' 



dorsal 



7 



2 



Length of its attachment 



. 1 



9 



?> 



., 



edge of gill-cover 



3 







Space between anal and caudal 



1 



11 



V 



J J 



nape 



2 



6 



Length of caudal lobes 



. 4 







» 



)? 



centre of orbit 



1 



7 



„ central rays of caudal 



1 



4 



» 



of axis of orbit 







8i 



Depth of caudal fork 



. 1 



9 



Page 122, to follow Cyprinus {Leuciscus) chrysoleucas. 



[130.] 



Cyprinus (Leuciscus) caurinus. 

 west Dace. 



(Rich.) North- 



Family, Cyprinoidese. Genus, Cyprinus. Sub-genus, Leuciscus. Cuv. 



This dace inhabits the Columbia River, and is abundant at Fort Vancouver, 

 from whence I have obtained two dried specimens through Dr. Scouler, and more 

 recently two preserved in spirits from Dr. Gairdner. The latter gentleman makes 

 no mention of it in his notes, and does not seem to have distinguished it from the 

 following species, of which examples were inclosed in the same vessel ; hence the 

 tints of colour in both, when fresh, may be supposed to be nearly the same. It is 

 very different from leuciscus gracilis in the size of its head, the form and size of 

 its scales, and other characters, being much more closely allied to the Common 

 European dace, from which, however, it may be readily distinguished by the fol- 

 lowing characters. 



DESCRIPTION. 



Form handsome, moderately compressed, circumference of the body greatest just before 

 the dorsal, where the height is equal to one-fifth of the distance between the tip of the snout 

 and end of the central caudal rays : the thickness there rather exceeds half the height. The 

 shoulders are thick and arched in profile. The head forms one-fourth of the length of the 

 fish, caudal excluded : the snout is rather obtuse, and projects a little beyond the shut mouth; 

 the orbit is nearly two of its diameters from the tip of the snout, and almost three diameters 

 from the most posterior part of the gill-flap. The under jaw shuts within the upper one, and 

 its tip is then more than the thickness of the upper lip, or above two lines posterior to the end 

 of the snout. Gill-cover rather broadly edged with membrane, rounded at the apex ; posterior 

 edge of operculum straight. 



