Compared iviih its Congeners. 2 1 7 



vary from forty-nine to fifty-one,* whilst it is well known 

 that the average in the salmon is between fifty-five and 

 seventy-seven. 



These data of themselves might be accepted as character- 

 istic of the specific differences between the fish in question 

 and the salmon, without reference to outward appearances 

 and colouring ; but as both also present important distinctions, 

 it is necessary to revert at greater length to their chief pecu- 

 liarities. At the same time, to a casual observer who is con- 

 tent to trust to external coloration, it must be admitted that 

 there is a decided resemblance in this respect between the 

 salmon grilse and the adult of the silvery salmon trout. In 

 form they also assimilate ; but the latter is the more elegant, 

 the head being contained five times in the total length. We 

 shall recur to the coloration presently ; but before doing so it 

 is necessary to compare our fish with the sea trouts. I sent 

 several specimens to Dr. Gunthur, F.R.S., in 1868, who, 

 after comparing them with the 5. trutta and its form 5. Cam- 

 briciis of England, informed me that, "It differs from S. trutta 

 only slightly in the shape of the gill covers, and from 5. Cam- 

 bricus in having a few more coeca — forty-nine. It has one 

 vertebra less than either of the two British species. The 

 fish has nothing to do with the salmon." The last remark, 

 as might be expected from what has been already detailed, 

 may be considered conclusive as regards the Silvery Salmon 

 Trout being a dwarfed race of *S. salar. 



But the interest connected with the silvery salmon trout, 

 either from a scientific or economical stand-point, requires 

 that all should be recorded of its characters and habits. 

 To proceed, therefore, with my personal examinations. The 

 head is rather long as compared with its depth ; I refer to 



* In four specimens, including two small and two full grown, the verte- 

 brae were invariably as stated, whereas the pyloric coeca were fifty in two 

 and forty-nine and fifty-one in the others. Gilpin says the latter are about 

 thirty, — evidently a mistake. 



