408 MK. P. DAT ON BRITISH SALMONES. 



followiug are the differences noted in the British-Museum Cata- 

 logue : — 



Salmo nigripinnis. Salmoferox. 



D. 14, A. 12, P. is, L. 1. 120-125, D. 13, A. 10-11, P. 16, L. 1. 125, 



C«c. 36-42 ; Vert. 57-59. Csec. 44-49 ; Vert. 58-59. 



Head small. Preopei-cle with an in- Head of moderate size. Pre- 



distinct lower limb. Snout not much opercle crescent-shaped, without 

 produced in males. No mandibular any angle (or distinct lower limb), 

 hook observed. Head of vomer with Snout much produced in males, 

 a transverse band of teeth, on body Mandibular hook when spawning, 

 generally a single series. Female Head of vomer small, toothless j 

 mature at 7 inches. Largest example body with a double or zigzag line 

 observed, 16 inches. of teeth. Caudal truncated at 18 



inches, in larger examples rounded. 

 Female mature at 14 inches. Lai'gest 

 example observed, 31 inches. 



These reputed two species have been found residing in nearly 

 or quite the same localities* in England, Scotland, "Wales, and 

 Ireland. The size of the specimens is important, as modifying 

 the conformation of the opercular pieces, as well as of the fins, 

 the character of the scaling, the proportional diameter of the 

 eye, and the existence, or the reverse, of teeth on the head of 

 the vomer, so frequently partially or entirely absent in the non- 

 migratory freshwater trout, more especially after attaining to a 

 large size. The teeth being present on the head of the vomer in 

 the smaller {S. nigripinnis) , but absent from the same place in the 

 larger ones (S.ferox), is merely symptomatic of edentulation due 

 to age. The same argument applies to the mandibular hook, it 

 being well known that among the Salmonidse this production is 

 absent in young males, as may be readily observed in the 

 parr Avhich possess milt ready for exudation and which has been 

 stated so long ago as by Willughby, aud proved by Shaw, to be 

 capable of fertilizing the ova of the salmon. The number of pec- 

 toral rays is of no consequence, as 1 find, even in the British- 

 Museum specimens, examples of 8. nigripinnis, S. ferox, and 

 S.fario possessing from 13 to 15. 



The foregoing leaves the following as Dr. Giinther*s primary 

 reasons for dividing these two so-called species : — S. nigripinnis 

 has D. 14, A. 12, head of the vomer toothed, and generally a 



-" Wallace (' Island Life," p. 322) observes that it is not found in Ireland, 

 but acknowledges Dr. Giinther as his informant ; while Irish examples exist in 

 the British Museum, and that habitat is admitted in the ' Introduction to the 

 Study of Fishes,' as well as in the British-Museum Catalogue. 



