468 SUPPLEMENT ON 



immoveable situation, which makes it a dangerous weapon, 

 the wounds of which are generally supposed to be venomous, 

 because they produce locked jaw, when the denticulations of 

 this organ lacerate severely. 



Its ilesh is white, fat, sweet, and of rather an agreeable 

 flavour. It was attempted to naturalize this fish at Stras- 

 bourg, and some were brought from Suabia with that intent. 

 The enterprise was abandoned, though it partially succeeded, 

 for individuals are sometimes received at Paris from Stras- 

 bourg, and other towns of the north, tolerably large and in 

 good condition. 



The Astroblepus grixalvii of Humboldt, though treated by 

 that naturalist in the zoological part of his travels as the type 

 of a new genus, appears to be a silurus. 



We insert a figure of a species of the subgenus Pimelodus, 

 P. cranchii, from a specimen in the British Museum. P. 

 cyclopum is copied from Humboldt's travels. 



In the genus Salmo, as it stood in Artedi, Linnams, Lace- 

 pede, and in most ichthyologists up to the present day, an 

 immense number of fishes were included, which, for the faci- 

 lity of study, are now divided into many subgenera. The 

 Salmon, or Trout proper, is the type of the family, and our 

 observations upon it will embrace nearly all that can be said 

 respecting the rest of the subgenera. 



All the fishes of this genus are carnivorous, and live for the 

 most of their time in fresh water. They seek in general the 

 purest and the quickest streams, those which roll over a sandy 

 bottom, or which fall in cascades in the midst of rocks. They 

 swim with the greatest facility, and struggle with success 

 against the most rapid currents. They possess the faculty of 

 shooting out of the water, and rising by prodigious leaps, 

 either in the air or in the water itself, for the purpose of re- 

 ascending the cataracts. 



The Salmon, (S> salar), is a fish too well known to need 



