i 

 NARRATIVE. 83 



descent,* but the stream is much compressed and moreover very 

 shallow, whence the great rapidity of the current at this spot. On 

 the opposite bank is a thin, straggling village, and a large building 

 belonging to the Hudson's Bay Company. 



Our explorations of the neighborhood showed a great abun- 

 dance of birds for the season. Prof Agassiz as usual had 

 got all the fishes of the neighborhood about him ; among others 

 several specimens of the gar-pike of Lake Huron, dried or in spirits, 

 were presented to him by the various coadjutors whom he had 

 interested in his favor. One of the most zealous of these was a fish- 

 erman whom he had captivated by a distinction (at first stoutly and 

 confidently combatted) between two closely-resembling species. In 

 the evening he unrolled his blackboard and gave us the following 

 account of them : 



" The gar-pike is the only living representative of a family of fishes 

 which were the only ones existing during the deposition of the coal and other 

 ancient deposits. At present it occurs only in the United States. The spe- 

 cies of South Carolina was described by Linnaeus as Esox ossein, from a 

 specimen sent to him by Dr. Garden. But it is not an Esox, though it has 

 the peculiar backward dorsal of that genus. It differs in the arrangement 

 of the teeth, which in Esox are seated on the palatal bones and the vomer, 

 but in this genus, Lepidosteus, on the maxillary and all other bones which 

 form the roof of the mouth. Moreover, the snout of the latter is much longer, 

 the upper jaw bones being divided into ten or twelve distinct pieces. The 

 intermaxillary is a small bone pierced with two holes for the admission of the 

 two anterior projecting teeth of the lower jaw. In Esox the scales are 

 rounded and composed of layers of homy substance, and overlap each other. 

 In Lepidosteus the scales are square and overlap only very slightly. Each 

 scale is composed of two substances ; first, a lower layer of bone, forming 

 that part of the scale which is covered by the next ; second, enamel, like that 

 of teeth. The scales are also hooked together; a groove in each, with a 

 hook from the next fitting into it. Nothing of this kind occurs in other 

 fishes of the present day. From these peculiarities I have named this 

 family the Ganoids. Their vertebrae are not articulated together as those 



* According to Bayfield the total descent is twentj-two and one-half feet, but 

 this probably includes both the Upper and Lower Rapids, as the whole difference of 

 level between Lake Superior and Lake Huron, in a distance of forty miles, is only 

 thirty-two feet. — Bouchette's British Dom. in N. America, L, 128. 



