11. coEEGONrrs. 185 



CoregOTnis albus, Lesimir, Journ. Acad. So. Philad. i. p. 231 (not 

 plate*); Richards. Frankl. Journ. p. 710, pi. 25. fig. 2 (very bad) ; 

 and Faun. Bor.-Amer. iii. p. 195, pi. 89. fig. 2 ; Dekay, Nat. Hist. 

 New York, iii. p. 247, pi. 7(3. fig. 240 ; Storer, Synops. p. 199 : Cuv. 

 8f Vol. xxi. p. 510. 



Most closely allied to C. lavaretus, but with the maxillary ex- 

 tending a Little further backwards. 



B. 9. D. 14-15. A. 14-16. L. lat. 80-95. L. transv. 10/12. 



The height of the body is contained three times and one-half or 

 three times and two-thirds in the total length (without caudal), the 

 length of the head four times and one-half or four times and two- 

 thirds. Snout of moderate length, obliquely truncated, with the 

 upper jaw projecting beyond the lower ; eye considerably shorter 

 than the snout. The maxiUary extends to below the anterior edge 

 of the eye, and its length is contained from three times and two- 

 thirds to four times in that of the head. The supplementary bone 

 of the maxillary is of moderate width and length, 

 oblong. The length of the mandible equals the 

 least depth of the tail. Back behind the head 

 ascending in a gentle curve. Pectoral nearly 

 as long as the head. 



Lakes of North America from Lake Erie to the Arctic Sea. 



a, h. Adult (22 inches long) and half-grown : stuffed. Albany 



River. Presented by Sir John llichardson. 

 c, d. Adult. Purchased. 

 e. Adult : stuffed. From the Collection of the Zoological Society. 



16. Coregonus richardsonii. 

 B. 9. D. 13. A. 13. L. lat. (72-) 77-80. L. transv. 10/12. 



Very similar in form to C. alhus. Snout of moderate length, ob- 

 liquely truncated, with the upper jaw projecting beyond the lower ; 

 eye shorter than the snout. The maxiUary extends to the anterior 

 edge of the eye, and its length is one-fourth of that of the head. 

 The supplementary bone of the maxillary is short, ^r— ^P=^ 

 broad, semicircular. The length of the mandible is ^--^[^ / / 

 a little less than the least depth of the tail. Pectoral \^.._J / 

 longer than the head, Avithout snout. ^ -"^ 



Arctic North America. 



a. Nineteen inches long : stuffed. Presented by J. Eae, Esq. 

 h-c. Nineteen inches long : stuffed. Erom the Collection of the 

 Zoological Society. 



This species is very closely allied to G. aVms, from which it differs 



* The author of tlie article on Coregonus in Agassiz, ' Lake Superior,' believes 

 that C. albus, Lesueur, was a species with prominent lower jaw, as represented 

 on the plate. But on carefully reading tlirougli Lesueur's text, and comparing 

 it with the figure, it appears to nie to be more probable that tliis plate has been 

 intended for C. artedi, and was misnamed C. albus, being published a long time 

 after the text. 



