T 6o SALMON AND TROUT. 



river has at this point a bed of gravel, whilst the tarns are 

 floored with a deep deposit of bog mud. A similar peculiarity 

 has been noticed as regards the black-moss trout of Loch 

 Knitching ; and Loch Katrine produces a small description of 

 very dark trout, which probably owe their discolouration, as in 

 many other lochs, to the drainage of the bog moors. 



Even on different sides of the same river I have found 

 complete differences in the colour and also in the edible quali- 

 ties of the trout, depending on the nature of the bottom soil ; 

 and a similar example, in the case of the fish of a small Irish 

 lake in the county of Monaghan, is mentioned by the author 

 of * Wild Sports of the West.' One shore was ' bounded by a 

 bog, the other by a dry gravelly surface. On the bog side the 

 trout are of the dark and shapeless species peculiar to "moorish" 

 loughs, whilst the other affords the beautiful and sprightly 

 variety generally inhabiting rapid and sandy streams. Narrow 

 as the lake is, the fish appear to confine themselves to their 

 respective limits the red trout being never found upon the 

 bog moiety of the lake, nor the black where the under surface 

 is hard gravel.' 



Notwithstanding, however, this almost infinite range of 

 variety in the yellow trout, depending upon local circumstances 

 of food, &c., we have only one really distinct species common 

 to both running and still waters, viz. Salmo fario, and one in- 

 digenous to lakes and similar situations, viz. the great lake 

 trout, Salmo fer ox. 



Dr. Giinther, of the British Museum, has * recognised ' 

 another separate species in the well-known Loch Leven trout 

 of Scotland, to which he gives the name of Salmo levenensis. 1 I 



1 The Loch Leven trout spawn in January, February, and March. I have 

 had opportunities of examining many specimens of the Loch Leven trout, and 

 their characters agreed closely with those given by Dr. Parnell from a specimen 

 one foot in length. Of these the principal were : 



Head a little more than one-fifth of the whole length, tail fin included. Depth of 

 body at the deepest part about equal to length of head. Gill cover produced behind ; 

 lower margin of operculum oblique ; pre-pperculum rounded ; end of the superior maxil- 

 lary bone extending as far back as the hinder margin of the orbit. Commencement of 

 back fin half-way between point of upper jaw and a point a little beyond the fleshy 

 portion of the tail. Fnd of back fin even, sometimes concave. Pectoral fins pointed 



