266 LAKE SUPERIOR. 



at once perceiv'ecl by attempting to compare the species of true 

 Loricarite with the Scaphirhynchus. I know very well, that the 

 affinities of Goniodonts and Siluroids with sturgeons are denied, but 

 I still strongly insist upon their close relationship, which I hope to 

 estabhsh satisfactorily in a special paper, as I continued to insist 

 upon the relation between sturgeons and gar-pikes, at one time 

 positively contradicted, and even ridiculed. I trust then to be able 

 to show, that the remarkable form of the brains of Silurid» comes 

 nearer to that of sturgeons and Lepidostei, than to that of any 

 other family of fishes. This being the case, it is obvious, that there 

 must be in the physical condition of the continent of America some 

 inducement not yet understood, for adaptations so special and so 

 different from what we observe in the Old World. Indeed, such anal- 

 ogies between the organized beings almost from one pole to another, 

 occur from man down to the plants in America only, among its native 

 products ; while in the Old World plants as well as animals have more 

 cii'cumscribed homes, and more closely characterized features in the 

 various continents at different latitudes. 



As for the species of sturgeons which occur in the Canadian 

 lakes, I know only three from personal examination, one of which was 

 obtained in Lake Superior, at Michipicotin, another at the Pic, and the 

 third at the Sault : though I know that they occur in all other Cana- 

 dian lakes, yet it remains to be ascertained how the species said to be 

 so common in Lake Huron, compare with those of Lake Supei'ior, and 

 with those in the other great lakes and the St. Lawrence itself. As 

 for the Atlantic species, ascending the rivers of the United States 

 west and south of Cape Cod, I know them to differ from those of the 

 lakes, at least from those which I possess from Lake Superior. The 

 number of species of this interesting family which occur in the United 

 States is at all events far greater than would be supposed from an 

 examination of the published records. Upon close comparison of the 

 specimens in my collection from different parts of the country, and 

 in different museums, as those of the Natural History Society of 

 Boston, of Salem, of the Lyceum of New York, my assistant, Mr. 

 Charles Girard, and myself have discovered several species not yet 

 deseribed. For this comparison I was the better prepared as I had 



