356 LAKE SUPERIOR. 



Fig. 1 represents this species of its natural size. 

 Fig. 2 is the lower surface of the head magnified, to show the con- 

 figuration of the mouth. 



From the Sault St. Mary, where it seems not to be infrequent. 



CATOSTOMUS, Lesueur. 



The study of the species of the genus Catostomus has become 

 quite as difficult as that of the genus Leuciscus, and for the same 

 reason ; the multiplicity of species. There are about thirty described 

 or mentioned, very few of which are accessible for comparison. 

 Hence, we are left, either to identify species which have only dis- 

 tant analogies, or to separate, on the other hand, some which have 

 the closest affinities. Which of these two obstacles is the most inju- 

 rious to science ? Doubtless the first ; since it leaves science in a 

 state of equivocal stability, during which no advance is attempted, 

 satisfied, as we are then, with our present attainments. 



In endeavoring to determine the different Catostomi from Lake 

 Superior, I began by comparing them with species already known 

 from the same geographical zone to which they would have the 

 nearest relations. One had been known for three quarters of a cen- 

 tury as an inhabitant of the gulfs of Hudson's Bay, and was described 

 by Forster under the name of Cyprinus Catostomus, which, forty- 

 four years later, became the type of the genus Catostomus, with the 

 specific appellation of C. Jludsonius, the author of this reform not 

 having known the fish otherwise than through the description and 

 the figure of Forster. 



In 1823, that is to say, about fifty years after Forster, Dr. Rich- 

 ardson gave a detailed description of the C. Hadsonius. He described 

 also another under the specific name of Forsterianus, and referred 

 to it as a synonymous variety of the preceding, indicated by Forster 

 himself. His specimens were from Lake Huron and from Slave 

 Lake. 



Among the species of Catostomi which I have brought from Lake 

 Superior, there are two which have a very great analogy, in their 

 general traits, with C. ffudsonius and Forsterianus. However, in 

 comparing them attentively and singly with the descriptions of Dr. 



