310 



NORTHERN ZOOLOGY. 











Dimensions. 









Inches. 



Lines. 





ength 



from 



tip of snout to tips of caudal 



. 15 







Length of labials • 



33 



33 



end of central rays of ditto 



13 



7 



,, lower jaw 



33 



33 



end of scales on ditto . 



. 12 



7 



Height of dorsal fin 



3J» 



,3 



end of adipose flu . . 



10 



10 



Length of its attachment 



33 



3) 



end of anal 



. 11 



1 



,, pectorals , 



33 



33 



anus . • 



. 10 







„ ventrals 



33 



3' 



ventrals . 



6 



10 



Depth of anal 



33 



J3 



dorsal 



. 6 



3 



Length of its attachment 



33 



33 



edge of gill-plate . . 



3 







„ lobes of caudal 



3? 



33 



nape . 



. 1 



11 



„ its central rays 



., 



33 



centre of orbit 



1 







Depth of caudal fork 



33 



of intermaxillaries vertically . 



. 



2 



„ body at dorsal 



Inches. 



Lines. 







»oi 



1 

 . 2 



4* 



3 



1 



. 2 



8* 

 3 



2 



2 



. 1 



5 



1 



3 



. 3 







1 







. 1 



5 



3 



10 



Obs. Though the species of Coregoni described in this work may be readily 

 distinguished when compared either in a recent or prepared state with each other, 

 yet there may be a difficulty in recognising any single species merely from the 

 descriptions, as the form, colours, and peculiar appearances of the scales are apt to 

 change in spirits, or when dried, and distinctions depending on magnitude are 

 strictly comparative ; it may therefore be useful to recapitulate some of the charac- 

 teristic marks which are less likely to vary. In C. alius and Lalradoricus the 

 lower jaw is equal to the upper one ; in C. tullilee, lucidus, and harengus, it is 

 longer ; and in C. quadrilateralis it is shorter. In C. alius the labials are equal 

 in length to the long axis of the orbit (the eye being removed), and their posterior 

 piece has a broad pyriform shape with the obtuse end down. In C. Lalradoricus 

 the labials have a similar form, but they are decidedly smaller, being shorter than 

 the axis of the orbit. In this species also the suboperculum is more cut away pos- 

 teriorly, and the head is proportionally smaller in all its dimensions. In C. tullilee, 

 lucidus, and harengus of the herring-salmon group, the labials have a more oblong 

 shape, being as wide close to their articulation as at their lower end ; and the 

 intermaxillaries are very narrow vertically, so that the edge of the upper lip is but 

 a very little way beyond or beneath the tip of the snout, according as the mouth is 

 shut or open. The depth of body of the tullibee is greater than in the other two 

 species, and its gill-plate, as mentioned above, has a different form. C. lucidus 

 and harengus can scarcely be distinguished from each other except in a recent 

 state. C. quadrilateralis may be known by its very small mouth, small labials, 

 short under jaw, and its peculiar shape of body, which, though flat on the sides, is 



