122 ARRANGEMENT. 



8EOUS Series be -arranges in two great subdivisions, 

 the Spiny-ji7ined and the Soft-JinnecL The whole 

 of the Spiny-finned go to form the First Order, 

 while the Soft-finned are divided into Three Orders, 

 according as the ventral fins are placed on the abdo- 

 men or belly, the thorax or chest, or, are wanting. 

 The Cartilaginous Fishes are divided into Two 

 Orders, — those with free gills, and those with fixed. 

 The great work, L'Histoire Naturelle des Poissons, 

 commenced in the year 1 828, by Baron Cuvier and 

 M. Valenciennes, and still in the course of publica- 

 tion by the latter gentleman, is not only an ampli- 

 fication of the summary account of fishes presented 

 in the Rcgne Animal of the former Naturalist, but 

 is also a modification and improvement of it in 

 many important respects. Should that great work 

 ever be completed, it will have effected, for the 

 Natural History of Fishes, what has not been ac- 

 complished in any of the other classes of Ver- 

 tebrata; affording a comprehensive and minute 

 account of all that is known regarding the history, 

 structure, and habits of the many thousand species 

 of the Class. That splendid work has now reached 

 the termination of the first great Order; and we 

 need scarcely state, that, throughout, we have been 

 most happy to avail ourselves of it, as a most trust- 

 worthy director and guide. 



