398 MR, r. DAY ox BEITISH SALMOXES. 



in Grioucestersliire and in Cornwall (S.cormiliensis), irrespective 

 of investigating the beautiful series in the British Museum. 



The various forms indigenous to this country, and usually 

 considered as pertaining to the genus tSalmo, have been thus 

 divided : — 



(1) Trutta, Nilsson ; Sahno and Fario, Cuvier. Salmon. 

 Anadromous forms, possessing at some period of their lives 



deciduous teeth on the vomer, which teeth are usually shed com- 

 mencing from behind forwards. 



(2) Solar, Cuvier. Trout. 



Freshwater non-migratory forms, possessing at some period of 

 their lives teeth on the vomer which are to a certain extent deci- 

 duous, the shedding of which commences from before backwards. 



(3) Salvelini, Nilsson. Charr. 



^Freshwater non-migratory forms, in which the vomerine teeth 

 are restricted to the head of that bone. 



The remarks which I have to make will refer to the second 

 group or subgenus of the genus Salmo, or Fario, our freshwater 

 non-migratory trout, respecting which I will commence by 

 observing that (excluding the Loch-Leven trout) we have only 

 one form, the /S^.y«riO, Linn., — S.ferox, Jardiue & Selby, S. nigri- 

 pinnis, Grlinther, B. stomacliicus, Grlinther, S. cjaJlivensis, Griinther, 

 and S. orcadensis, Giinther, being simply varieties which, due to 

 local circumstances, have developed certain changes, some of 

 which appear at first sight to be permanent, others to be 

 transitory. 



If we examine into the history of these fishes as given by our 

 various British authors, we find as follows : — 



Donovan, in his 'British Eishes ' (1802-1808), refers to the 

 common trout (Salmo fario) , which he observed was subject to 

 many varieties, differing in appearance according to the season of 

 the year and also the nature of the water it inhabited. He 

 commented on a, form existing at Llyndivi, a lake in South "Wales, 

 where it was termed " Coch y dail " (it was marked with black 

 spots as large as sixpences) ; to a crooked-tailed variety in the 

 Eynion, a river not far from Machynlleth, as well as to its being 

 found in the Snowdon lakes ; to the Grillaroo trout of Ireland, 

 remarkable for the great thickness of its stomach, though it does 

 not differ in other respects from the common trout ; and, lastly, 

 to some in the Scotch lakes that are very differently coloured 

 externally from the common sort, and which he suspected might 

 be a distinct species. He next alluded to the variation of trout 



