SALMON— DENTITION AND FINS. 



53 



Teetli — in a single row in the jaws and palatines : 

 rather stouter than those in the mandibles, while the 

 are still smaller. In adiilt.s the teeth are often larger 

 in those of the females, 

 while there are from one 

 to three teeth (unless all 

 are absent) on or just 

 behind the head of the 

 vomer * : in grilse, should 

 teeth be present, there 

 are from one to three 

 on the head and one or 

 more in a single row 

 along the body of that 

 bone. But the numbers 



are very various so soon 

 as the fish arrives at an 

 age to commence its mig- 

 rations sea-wards. In the 

 parandsmolt a double row 

 exists along the body of 



Fig. 16. 

 Teeth on 

 vomer of 

 grilse, 3J 

 lb. wt. 



the premaxillary ones being 

 maxillary and palatine ones 

 in the jaws of males than 

 the vomer, while the hind 

 edge of the head of that 

 bone is armed with three 

 or rarely four teeth placed 

 in a single row : some 

 of these commence being 

 shed as the par is becom- 

 ing a smoltjt and the loss 

 I'apidly increases in the 

 grilse stage. As a rule 

 there are less teeth on 

 the head of the vomer of 

 a salmon than exists in 

 that of a trout of similar 

 size. There are three to 

 six recurved teeth on 

 either side of the tongue. J^ 



Fig. 17. Outlines of tail fins of salmon at various ages ; — 

 1. Male par, 4''2 inches long; 2. Par, 5'2 inches long; 3. 

 male par, 6-4 inches long ; 4. male smolt, 7'S inches long ; 

 5. Grilse, 3} lb. ; 6. Grilse, 4^ lb. 



* July 12tli, 1886, a grilse of 3J lb. weight had two teeth on the head of the vomer and one on 

 its body : vertebra; .59 -f- .r : one of i^ lb. had only two on the hind edge of the head of that 

 bone : while a large male salmon, 2G lb. weight, had one tooth on the hind portion of the head of 

 the vomer and a second on the commencement of the body of that bone. 



t In several par seven inches long taken in September, 1886, the teeth on the body of the 

 vomer were commencing to take on a single row in all, for out of nine sets originally of two each 

 only four pairs remained, tlie rest having become single. 



J In June, 1883, a female salmon of 10 lb. weight had three teeth on either side of the tongue : 

 July 21st, 1886, a female salmon 12 lb. weight had the lingual teeth aU shed. Parfitt, Fauna 

 of Devon, 187.5, jjage 9, observed, "Notice is taken by Mr. Couch and others of salmon having 

 teeth on their tongue: but, so far as I know, no one has taken notice of salmon of the same size 



