96 BRITISH FRESHWATER FISHES 



the greater part of the 9 miles of its length Loch 

 Rannoch is a very deep lake, from 350 to more 

 than 500 feet deep. 



Other lakes belonging to the Tay system are said 

 to contain Char, which may be similar to the Struan. 

 Char were at one time pretty plentiful in Loch 

 Leven, but have long been extinct, the last being 

 captured in 1837; it is noteworthy that this ex- 

 tinction followed an extensive drainage operation in 

 1830, which reduced the area of the lake to three- 

 fourths of its original dimensions, and decreased its 

 depth by 4 J feet. 



The Haddy {Salvelinus killinensis), of Loch 

 Killin in Inverness-shire, is one of the most distinct 

 species of Char in the British Isles. Loch Killin is 

 quite a small lake, and its greatest depth is only 

 67 feet ; nevertheless, its Char grow to a considerable 

 size, attaining a length of 16 inches. I have figured 

 a male of only 8 inches (PI. X, Fig. 2), for better 

 comparison with a Struan of nearly the same size. 



In the blunt snout and the subterminal mouth, 

 with the lower jaw shorter than the upper, this fish 

 resembles the Struan, but differs from that species in 

 the stronger maxillary, the smaller size of the eye, 

 and the greater width of the interorbital region. 

 It has a rather clumsy form, as the head is large 

 and obtuse, and the body deep and but little com- 

 pressed. The fins are large, especially in the males, 

 and the scales are smaller than in most British 

 Char, numbering 180 to 220 in a longitudinal 

 series. The coloration is rather sombre, the back 

 and sides olivaceous or plumbeous, the belly silvery 

 or yellowish. 



