142 NORTHERN ZOOLOGY. 



answered in the negative. I was shown a fish of the smallest size, which had in proportion 

 as large a hook to the lower jaw as the largest. I inquired whether the hooked salmon were 

 furnished with roe or milt. I was answered they had always milt. On opening seven of 

 them I found this verified ; whereas four salmon which were not hooked had roes. The 

 hooked or male salmon is so called because the point of its lower jaw is bent inward and has 

 a taper form resembling a finger, while, on the contrary, the upper one is formed with a cavity 

 to receive the point, embracing it like a sheath for about half its length." 



The Bull-trout of the Tweed is in little repute for the table ; and Cuvier says that the flesh 

 of the Salmo hamatus, though red, is not so rich as that of the Common salmon, and is held 

 in less estimation. The Bull-trout of the Orkneys is also said to have the flesh hard and 

 dry, and consequently to be little sought after by the country people ; but as it had not 

 entered Loch Stennis in the spring, at which time the other trouts of that lake were sent to 

 me, I have not been able to procure a specimen, and am consequently ignorant how far it 

 resembles the Tweed fish bearing the same name. 



5. Nith Trout, &c. Plate 92, f. 2, A and B, exhibits the head of a trout which was 

 taken in the latter end of December in the river Nith. The entire specimen measured four- 

 teen inches to the tips of the tail, or twelve inches and a half to the end of the scales on the 

 base of the caudal fin. Figure 4, A and B, represents a young fish from the Clouden, a tri- 

 butary of the Nith : it measured seven inches to the end of the scales on the caudal, and 

 three-quarters of an inch more to the tips of that fin. I have received fine specimens of pre- 

 cisely the same kind of trout from Loch Crosspiel, below the manse of Durness, Loch Kes- 

 caig, which discharges its waters into the Atlantic near Sandwood in Sutherlandshire, and 

 from Loch Stennis in the Orkneys. It is a handsome fish, not so deep in the body as the 

 Salmon-trout, and assuming a different general aspect, from its much darker colours and its 

 smaller scales. The colour of the back is a dark mixture of oil-green and brocoli-brown, the 

 sides are greatly paler, and the belly is whitish with dusky shades. In some localities, or at 

 certain seasons, the sides have a reddish-brown tinge, and the belly is more or less deeply 

 glazed with orange. The forehead, snout, and gill-covers are crowded with rather large 

 round or oval blackish -brown spots, and there are many roundish or stelliform marks on the 

 back and sides, for some distance below the lateral line, some of which are surrounded by a 

 paler circle, or tinged with aurora-red. The dorsal is variegated by several rows of smaller 

 brown spots of different shades, and the adipose fin and upper lobe of the caudal are also 

 spotted. The scales have an oval form, are considerably smaller, less flexible, and not so 

 caducous as those of the Salmon-trout, and have a beautiful golden lustre. In the dried 

 specimens an acute, prominent median ridge extends from the nape nearly to the tip of the 

 snout, and the lateral ridges of the cranium are also conspicuous : in the fresh state, the head 

 is smooth and rounded above, and the snout is very obtuse. The under jaw is exactly equal 

 in length to the upper surface of the head. The vomerine teeth run back in a double row 

 about half way to the gullet, and there are six teeth on each side of the tongue. The head 

 in the females constitutes somewhat less than one-fourth of the total length excluding all the 

 caudal beyond the scales : in the males the head is larger, four of its lengths extending from 



