ME. F. DAY ON BEITISH SALMONES. 411 



It now becomes necessary to consider the relationship existing 

 between S. nigripi7inis, S. orcadensis, S. ferox, and S. fario. 

 Among our earlier British ichthyologists we find that Berken- 

 hout (Sym. 1795, p. 79. sp. 3) termed the "great lake-trout" 

 S. lacustris, sujjposiug it to be identical with the continental 

 variety ; but of late years differences have been asserted to exist 

 between the British and foreign race. Jardine and Selby termed 

 ours S. ferox, as will be seen in the 'Encyclopaedia Britan.' (edi- 

 tion vii., art. "Angling," p. 142) and in the ' Edinburgh JS'ew 

 Philosophical Journal ' (xviii. p. 55), the specific name having 

 been chosen to characterize its size and voracious habits, I have 

 already alluded to Jurine's opinion of the specific identity of all 

 these forms in the Lake of Geneva ; and it would be but reason- 

 able to expect that if the British S. fario under favourable con- 

 ditions could attain the size of S. ferox, the continental 8. fmno, 

 which is the same species, would, under like conditions, also 

 arrive at being a great lake-trout. Collett (1875) in Norway, 

 Eeddersin in Denmark, Moreau (1881) in France, can only see in 

 the numerous races of freshwater trout varieties, and not species ; 

 while the last author (vol. iii. p. 534) places among the syno- 

 nyms of Trutta (or Salmo) fario, " La Eorelle du LacLeman, Fario 

 Lemanus ;" and at p. 536 observes, " La Truiteferoce, Trutta ferox, 

 Valenc, des eaux du Eoretz est une simple variete de la Truite 

 ulgaire, et nullement une espece particuliere." 



Although these authors have, in my opinion, been perfectly 

 correct in their views, still there existed this fact, that Dr. 

 Griinther had given structural differences existing among the 

 specimens in the British Museum, showing that S. ferox pos- 

 sessed 56 to 57 vertebrae and 43 to 49 caeca, while 5". fario had 

 57 to 60 vertebrae and 33 to 47 caeca. I have, however, now 

 shown that examples of S. fario may have from 56 to 60 vertebrae, 

 and likewise from 33 to 54 caeca, tlms overlapping the entire 

 amount of variations as described. 



What differences have been brought forward to differentiate 

 8. ferox from large examples of ^S*. fario ? Sir William Jardine 

 stated that "the dorsal fin contains 15 rays, and appears to be 

 constant in that number ;" and that " in form it is generally 

 shorter proportionally and deeper than large specimens of S. 

 fario." Sir J.Bichardson distinguished between the great lake- 

 trout and brook-trout by the size it attains. The tail " in adults 

 id perfectly sq^uare, or miglit even be described as slightly rouuded 



