NARRATIVE. 25 



This trout belongs to the CYCLOIDS. In this division there are only 

 two families which have spinous rays in their fins, (the tautog and the 

 mackerel.) We have before us specimens of two families of Cycloids. 



1. Salmonidce. Distinguished by having the intermaxillary and upper 

 maxillary in one row, which seems to me to indicate the highest rank 

 in the class of fishes. They all have a second dorsal, of an adipose struc- 

 ture. The anterior dorsal and the ventrals are in the middle of the body. 

 Genus Salmo : characterized by teeth on every bone of the mouth and on 

 the tongue. There is but one genus in the class of fishes that has teeth on 

 more bones than the salmon. In no genus are the species more difficult to 

 distinguish. Sixteen species have been described as belonging to Europe, 

 which I have been obliged to reduce to seven. The same species presents 

 great variety of appearance, owing to difference of sex, of season, food, color 

 of the water in which they live, &c. In this country I have examined two 

 species, the brook trout, (. fontinalis,) the spawning male of which has 

 been improperly separated as S. erythrogaster ; and the present species, the 

 Mackinaw trout, S. amethystus of Mitchill. Dekay has described a variety 

 of this species, as S. affinis. In this species the appendices pylorici before 

 spoken of are very numerous. The small intestine arises from the lower 

 extremity of the stomach, and curves only twice throughout its length. The 

 gall-bladder is very large : the liver forms one flat mass ; the ovaries and 

 kidney extend along the whole spine. All this family spawn in the autumn. 



"(2.) Cyprinidce. Like the salmons they have the ventral and dorsal fins 

 in the middle of the body, but no adipose dorsal. Branchiostegal rays, 

 three. Upper maxillary forming another arch behind the intermaxillary. 

 Teeth only on the pharyngeal bone behind the gills, at the entrance of the 

 oesophagus. No pyloric appendices. Intestine long and thin, as in all her- 

 bivorous fishes. Air-bladder transversely divided into two lobes, communi- 

 cating by a tube with the intestinal canal.. 



" This family is the most difficult one among all fishes. As yet there is 

 no satisfactory principle of classification for them. I have studied them so 

 attentively that I can distinguish the European species by a single scale ; 

 but this not from any definite character, but rather by a kind of instinct. 

 Prof. Valenciennes, a most learned ichthyologist, has lately published a vol- 

 ume on this family, in which he distinguishes so many species, and on such 

 minute characters, that I think it now almost impossible to determine the 

 species, until all are well figured. 



" Here are specimens of two genera : (a) Leuciscus, with thin lips ; only 

 one species here, an undescribed one characterized by a brownish stripe above 

 the lateral line. (6) Catostomus, with very thick lips and prominent snout." 

 3 



