322 VERTEBRATES : FISHES. 



eggs, and defend them with great spirit ; but most 

 abandon them as soon as laid. With few exceptions, 

 Fishes have no care of their young, but devour them 

 as readily as they do any other food. In the Sygna- 

 thi, or Pipe-Fishes, the eggs are conveyed into a pouch 

 under the abdomen or at the base of the tail of the male, 

 where they are hatched. 



Although the lowest class of the Vertebrates, their 

 varied forms, and colors which often rival those of pre- 

 cious stones and burnished gold, the wonderful power 

 and velocity of some, the wholesome food furnished by 



many, and the exciting sport of their capture, combine to render Fishes subjects of 

 great interest to the casual observer, as well as to the amateur and the professional 

 naturalist. 



The number of known species of Fishes is about twelve 

 thousand. According to the earlier writings of Agassiz, 



they are divided into four orders, the scales being taken as the basis of classification, as 

 follows : Ctenoids, embracing fishes which have the scales toothed on the edge, as Perch, 

 Breams, Bass, etc. ; Cycloids, comprising fishes whose scales are rounded and smooth on 

 the edge, as Salmon and Cod ; Ganoids, embracing fishes with enamelled scales, as the 

 Gar-pike ; and Placoids, fishes with fine point-like or stellate scales, as Sharks and Skates. 

 Cuvier divides fishes into two great groups, Bony and Cartilaginous Fishes, which 

 together include nine orders ; and since so many of the books upon natural history to 

 which the student may have occasion to refer follow him more or less closely, and as there 

 is no generally accepted classification of this important group of animals, I have thought 

 it best to adhere mainly to his arrangement.* 



Bony Fishes, or Fishes proper, are those with a true 

 bony skeleton, and include six orders, as follows : 



* A much more recent classification than Cuvier's is given in this foot- 

 note. It is essentially that of Miiller as modified by Owen and others. 



For the Families, see Appendix, page xiii. 

 Plagiostomi (Elasmobranchii) (Rays and Sharks) \ 



f-r , ,.,, . v { oELACHIANS* 



Holocephah or Chimaeroids (King of Herrings) ) 



Protopteri or Sirenoids or Dipnoi ( Lepidosiren ) . 



Ganoids (Sturgeon and Gar- Pikes) } GANOIDS. 



Lophobranchi (Pipe-Fishes, Sea-Horses, &c.) 



Plectognathi (Puffers, &c.) 



Acanthopteri (Perch, Bass, &c.) , 



Anacanthi (Cod, Haddock, &c.) 



Pharyngognathi (Tautog, &c.) 



Malacopteri (Salmon, &c.) 



Dermopteri (including Marsipobranchii) (Lamprey, &c.) \ DERMOPTERS. 



