GENERAL DESCRIPTION. 145 



markings, and with a very faint indication of dusky red on 

 the margins. 



Altogether, the Siskawitz is a greener coloured and less 

 lustrous fish than the Namaycush, and far less distinctly 

 spotted ; still there is so much similarity, that by a person 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 Mackinaw 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 towards the snout, is short, 

 thick, and very obtusely rounded, giving it a coarse and clumsy 

 profile, and distinguishing it decidedly from the kindred species. 

 On the shoulders it is moderately broad, with the sides some- 

 what 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 marked in this, as are the radiating processes on the 

 operculum and pre-operculum. 



The pre-operculum is considerably 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 

 maxillary 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 



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