296 LAKE SUPERIOR. 



This species is very closely allied to the G-rystes salmoides of the 

 Southern States,* from which it is however distinguished by the 

 profile of the more raised back, and of course by a broader body. 

 The surface of the skull is uniformly rounded and not depressed as 

 as in G-. salmoides. The proportions of the head compared with 

 the body are the .same as in this latter, but the mouth is less opened 

 and the shorter labials do not reach a vertical line drawn across the 

 hinder margin of the orbits, whilst they exceed such a line in 6r. 

 salmoides. The teeth are arranged like cards, and are similar in 

 both species. 



The fins upon the whole seem to be cut on the same pattern as in 

 6r. salmoides, but when we examine them attentively we see that 

 they are all stabbed like the body itself, the ventrals and pectorals 

 shorter and more widened, the dorsal and anal lower. As for the 

 other details of their structure they are about the same, as we may 

 see from the following formula. 



Br. 6 ; D. X. 14 ; A." Ill, 10 ; C. 7, I, 8, 7, 1, 6 ; V. 1, 5 ; 

 P. 16. 



The scales are a little smaller, but of the same form as in 6r. 

 salmoides; the radiating struie are perhaps less marked. They 

 cover the opercular apparatus and the cheeks, but at this latter 

 place their smaller size is quite remarkable ; this latter character 

 is very striking when we compare both species. 



Our specimens are from Lake Huron ; one of them measures 

 twelve inches, and the other seven. I have also received two speci- 

 mens from Lake Michigan, through the care of Mr. Samuel C. 

 Clarke, the largest of which measures eighteen inches. Professor 

 Baird forwarded to me specimens from Lake Champlain. Dr. De- 

 kay has found it in Lake Oneida. Finally, this species extends 

 to Pennsylvania, as I was able to convince myself by two speci- 

 mens collected at Toxburg, and for which I am under obligation to 

 Professor Baird. 



* Grystes salmoneiis does not occur in the Northern nor in the Middle States, al- 

 though Dr. Dekay mentions it upon the authority of Cuvier, who probably mistook 

 specimens of our Grystes fasciatus for the southern species. Having, however, failed 

 to discover this confusion, Dr. Dekay describes the same fish again, under the name of 

 Centrarchus obscurus. 



