68 The Natural History of the Salmon. 



spots. As far as can be judged by studying the 

 various works on the Salmonidae, Gunther, Chol- 

 mondeley Pennell, Day, and others, these may be 

 divided into three classes. 



FIRST. Those with single series of vomerine teeth, 

 mostly disappearing at mature age, as the salmon 

 (Salmo salar\ the sea trout (Salmo trutta], and, if 

 the bull trout (Salmo eriox) is a distinct species, it 

 may be put into this class. 1 The teeth of these are 

 gradually lost, but for some time from one to four 

 remain. In the large salmon, from the examination 

 of a great number, I have generally found the teeth 

 on the vomer are absent or reduced to one. These 

 species are all migratory, and are all found in Great 

 Britain ; but the same distinctive difference is to be 

 found in all foreign migratory salmonoids, as the 

 so-called Salmo argenteus from the Atlantic rivers 

 of France, Salmo mistops from Norway, Salmo vener- 

 nensis of Sweden, etc. 



SECOND. Those with single series of vomerine 

 teeth, persistent during life, viz., Salmo Orcadensis, 

 the Orkney trout. Salmo ferox, the Great Lake 



1 Some suppose the bull trout is a hybrid, but if so, it cer- 

 tainly propagates its species, or from whence come the enor- 

 mous number which frequent the Tweed and its tributaries ? 

 Dr. Gunther makes Salmo eriox and Salmo Cambricus the 

 same, but the Sewin and the Sea trout rarely attain a very 

 large size. The bull trout, on the contrary, often reaches 

 from 20 to 30 pounds. 



