SALMONIDJE. I 13 



Tiding into a dull cbad white, which is the prevailing hue of the belly, 

 with a very slight silvery gloss on some of the scales. 



The dorsal and caudal fins are of the same greenish brown with the 

 back, and like it are irregularly patched with lighter spots. The pec- 

 toral, ventral and anal fins are paler, but with the same markings, and 

 with a very faint indication of dusky red on the margins 



Altogether, tho Siskawitz is a greener colored and less lustrous fish 

 than the Namaycush, and far less distinctly spotted ; still there is so 

 much similarity, that by a pjerson not accustomed to look for nicer 

 and more permanent structural distinctions, the two species might be 

 very readily confounded. 



In form, the Siskawitz is rather shorter and stouter than the Mack- 

 inaw fish, and does not taper nearly so much at either extremity. The 

 head particularly, which in the other is very small, neatly shaped, 

 and depressed toward the snout, is short, thick, and very obtusely 

 rounded, giving a coarse and clumsy profile, and distinguishing it de- 

 cidedly from the kindred species. On the shoulders it is moderately 

 broad, with the sides somewhat compressed. The length of the head 

 is about one-fourth of the whole length of the fish, from the snout to 

 the tips of the caudal. The skull is strong and bony, with powerful 

 lower jaws. The porous lines and foramina of the bones, seen on the 

 heads of several of the other Trouts, are very evident and distinctly 

 marksd in this, as are the radiating processes on the operculum and 

 preoperculum. 



The preoperculum is considsrably rounded and almost vertical ; 

 the posterior free margin of the gill-covers is nearly semicircular, 

 much less acute posteriorly than in the Namaycush. 



It has a very complete and formidable dental system, all the max- 

 illary and palatine bones, as well as the lower jaws and either side of 

 the tongue, being armed with strong, sharp, curved teeth, and the 

 vomer provided with a double line extending along the whole length 

 backward. The dorsal fin is situated nearly midway the whole length 

 of the body ; the posterior dorsal is thicker and more clumsily shaped 

 than in the preceding species. The caudal fin is deeply forked. 



The number of rays in the several fins I am, I regret to say, unable 

 to supply at present. 



Neither in coloring nor in form, therefore, does the Siskawitz equal 



