..... 



726 APPENDIX. [No. VI. 



Teeth. — The two largest teeth of the upper jaw project on each side of the snout, 

 like the canine teeth of some quadrupeds, and are visible when the mouth is closed, 

 having formed for themselves depressions in the lower lip. These teeth stand on the 

 intermaxillaries, which form, with the lower jaw, the whole margin of the mouth. 

 The intermaxillaries are further armed with a single crowded row of smaller teeth, 

 and the lower jaw has a thin row of teeth, similar to the two remarkable ones in the 

 upper jaw. A set of strong distant teeth are also arranged, somewhat in a horse- 

 shoe form, on each side of the roof of the mouth, and across the vomer, so as to be 

 nearly opposed to those in the lower jaw. These teeth are situated upon the pala- 

 tine bones and vomer, and, like those on the jaws, are somewhat hooked, with their 

 points directed backwards. The tongue is smooth. 



The branchiostegous membranes overlap each other, at their insertion into the root 

 of the tongue. They contain seven rather distant cylindrical curved rays. The three 

 inner branchial arches are furnished with double rows of tubercles, covered with mi- 

 nute teeth. The outer arch has a single row of similar protuberances, and also a 

 row of processes about half an inch long, which are armed on their inner surfaces 

 with small crowded hook-shaped teeth. The superior andinferior pharyngeal bones 

 are also rough, with minute teeth. 



Fins. — The first and second dorsal are about an inch apart, differing in this respect 

 from Bloch's figure of the P. fiuviatilis, t. 52. The former fin is the highest, and its 

 rays are spinous. Those of all the other fins are articulated — 



B. 7. P. 14 or 15. V. 6. D. 15—21 or 22. A. 13. C. 16 or 18. 

 The dimensions of an ordinary-sized fish were — 



Length to caudal fin - - - - 19 inches. 



to anus 12 



— of caudal fin 3 



Height of 1st dorsal fin - - - 2 J 



2d do. do. - 2 



Length of alimentary canal from pharynx to anus, 20 

 The perch spawns in May. It is very abundant about Cumberland-House. We 

 did not observe it to the northward of Great Slave Lake. 



Cottus Hexacornis. Six-horned Bull-head. 



The body is much less than the head, roundish and tapering to the extremity of 

 the tail. The lateral line is rough, and runs near the back. There is a row of small 

 orbicular scabrous bony plates between it and the back ; the row is double, opposite 

 to the second dorsal fin. There are no other perceptible scales. 



