No. VI.] 



NOTICES OF THE FISHES. 



707 



The gill-openings are large, and the branchial arches unite nearly at the mcesial 

 line of the tongue. There are ten oblique rays in the brahchiostegous membranes. 



The intestines are similar in form to these of the trouts. The stomach is rather 

 small. The caeca, from thirty to thirty-six in number, are simple, cylindrical, and 

 from one to two inches long. 



Fins.— The dorsal fin is situated opposite to the ventrals. The anal fin is triangular 

 with the apex of the triangle truncated ; it has eighteen rays. The caudal fin is large 

 and very entire, truncated with a slight rounding of the angles, and entirely devoid 

 of a crescentic form. Its outline is wedge-shaped. 



This fish is inferior to the English salmon in size, its flesh is red, and it is taken in 

 great abundance in the months of July and August, in the Salmon Leap, at Bloody 

 Fall, on the Copper-Mine River. 



We have compared it with the descriptions of the various species given in Pallas' 

 Itin. ; and with the plates of those indicated by Cuvier, Reg. Animal, ii. p. 162, from 

 all of which it appears sufficiently distinct. It resembles the S. Eriox in its 

 caudal fin. 



Salmo Mackenzii. 



Inconnu, Mackenzie's Voyages in North America, p. 9, and elsewhere, and of the Canadian Voyagers. 

 S. corpore sub-tereti elliptico-lanceolato, capite lougo : rostro truncate, ore dentibus parvis confertis 

 munito, maxilla inferiore longiore.— Tab. xxv. Fig. 1. 



Body roundish : lateral outline betwixt elliptical and lanceolate, tapering towards 

 the tail. Lateral line straight. 



Colour of the back and sides changing from bluish to greenish-grey when it is 

 moved in the light: of the belly bluish-white. 



Scales sub-orbicular, four lines in diameter, possessing much pearly lustre. 



The head is long and compressed, but a little flattened above. The vertex is 

 covered with smooth skin. The msesial line rises into an acute smooth ridge betwixt 

 the orbits. The orbits are oval and large— they are placed about an inch from the 

 extremity of the snout, or twice as near to it as to the posterior edge of the opercu- 

 lum. The sides of the head have a strong silvery lustre. The operculum and sub- 

 operculum form, by the junction of their smooth even posterior margins, a very 

 regular segment of a circle rather greater than a semicircle. They form about one- 

 third of the margin of the large gill openings, the remaining two-thirds being 

 formed by the branchiostegous membranes. The pre-operculum has a lunated form, 

 and leaves a small naked cheek not greater than its own breadth betwixt it and a 

 double range of suborbitar bones. These sub-orbitar bones, about six in number, form 

 a circular patch, the greatest part of which lies posterior to the orbit ; a narrow thin 

 plate, running out from them along the under margin of the orbit, again expands into 



4X2 



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