116 PHTSOSTOMI. 



while it is here that Dr. Giinther counts. Although in 8 of my British examples 

 the difference in the number of pierced scales along the lateral-line does not exceed 

 20, I find from 185 to 235 rows descending to the lateral-line, or a variation of 50 

 scales. Taking the whole of the repnted British species, the extreme variation 

 recorded is 70 rows. If, therefore, among 8 examples of American charr received 

 from two localities I can observe a difference in number of at least 50 rows of 

 scales descending from the back to the lateral-line, the extreme variation of 70 

 among specimens of charr obtained throughout the extent of Great Britain and 

 Ireland appears hardly sufficient grounds for instituting distinct species. Sir 

 W. Jardine considered that " the northern, or Sutherland charr," has more elon- 

 gated scales than the " southern charr," the scales of which he described as being 

 more orbicular. 



" The charr of Hawswater," observes Dr. J. Davy, " which is known to feed 

 a good deal on insects, is a small and slender fish in comparison with the charr of 

 Windermere, which feeds more at the bottom and has a less precarious supply, 

 especially of Squillce, which abound in the lake. The one takes the artificial fly 

 freely ; the other — that of Windermere — is rarely so tempted and seldom caught, 

 except by trolling with the minnow. In short," he remarks, " so various are they 

 that in no two lakes do they perfectly agree, either in their average size, form, 

 colouring, or even in their habits." In examining 8 examples from the above 

 locality I found the following variations : — D. /.^, A. J-If, L. 1. 118-128, Ccec. pyl. 

 (in one example) 28, (32-44, Giinther). The number of rows of scales descending 

 to the lateral-line varied from 166 to 180. Passing on to the Loch Rannoch charr, 

 8. struanensis (Maitland), we see certain differences present (see plate cxvii, 

 fig. 2). 



D. -§-, A. f---f » Ij- 1- 120, Coec. pyl. 28, 160 scales descended from the back to 

 theL.l. 



The fins in some examples are more developed than in others, and may be said 

 to be in many respects intermediate between 8. alpinus and S. killinensis, but the 

 most peculiar feature is the dark colour of the specimens. Among the examples 

 sent to me by Sir J. Gibson-Maitland was a common trout from Loch Rannoch, 

 which showed the same dark colours and well-developed fins. The eye in some of 

 these charr was rather large, which, taken in conjunction with the dark colours of 

 the body and somewhat developed fins, would seem to indicate its living at some 

 considerable depth. 



Names. — Charr or char. Torgoch ("red belly"), Wales. Red-iuame, Scotland. 

 U ombre-chevalier, French. 



In olden time the credulous were taught that three sons of the Church intro- 

 duced these fishes into Wales from Rome, and placed two in each of the Lakes of 

 Llanberris, Llynumber, and Trevennyn. 



Habits. — A gregarious and usually deep swimming fish, shy of taking a bait 

 and feeding largely at night-time. The common food of the trout has been found 

 in its stomach, while when in confinement it can be similarly fed. It appears to 

 require very pure and mostly deep water for its residence, but is found in some 

 Irish lakes which are not very deep. 



It has been observed to have disappeared from some lakes due to the entrance 

 therein of poisonous matter as from lead mines,* but in other localities where no 

 such deleterious substances have obtained access, as Loch Leven, and some of the 

 Irish Loughs, it has been suggested that such may be dependant upon the 

 diminution or disappearance of such entomostraca as previously formed its 

 natural food. It does not bear confinement well, but may be kept for a short 

 period in troughs through which a supply of water flows. Thompson, in 1835, 

 observed that they were thus kej)t at Coniston water at the hotel and sold at 10s 

 a dozen. 



Charr have been accused of destroying the eggs and young of the trout. 



Knox found in examples from Windermere some entomostraca. Sir J. 



* It has been stated to descend to the sea, and it has been asserted that some were captured 

 there or at the mouths of rivers on the Welsh coast after they had been driven out of Llanberris by 

 poisoned waters. Further evidence on this point is required. 



