174 OUTLINES OF ICHTHYOLOGY. 



These names take their origin from the Latin 

 words acicula, a small needle ; subula, an awl ; 

 villus, a fleece ; cilium, an eye-lash ; seta, a bristle 

 or brush ; radula, a scraper ; cants, a dog ; mo la, a 

 mill. 



FISH CLASSIFICATION. 



Fish are divided into i. Series; 2. Orders; 

 3. Families ; 4. Genera ; and 5. Species. 1 



The two grand series of fishes consist of 



(i.) Those possessing bony skeletons, which are 

 called true, or bony fishes ; and 



(2.) Those which have skeletons of cartilage or 

 gristle, which are called cartilaginous fishes, or 

 chondropterygii. The latter also want some bones 

 of the jaws, and have other peculiarities. 



The TRUE or BONY FISH are divided into 

 six orders, viz. : 



ORDER I. 



ACANTHOPTERYGII, or Spiny-finned fish. (From Gr. acantha, 

 a spine, and/ferjgifaf, a fin.) 



In this order the first portion of the back fin, or first back 

 fin, when there are two, always has spinous rays or supports 

 which are also found in the anal and ventral fins. 



This Order contains Fifteen Families. 



The MALACOPTERYGII, or Soft-finned fish (from the Gr. 

 malacos, soft, and pterygion, a fin), furnish three Orders founded 

 upon the position of the ventral fins, viz. : 



1 Sometimes, for the sake of convenience, Families are fur- 

 ther separated into Divisions or Sub-Divisions, and Genera 

 into Sub-Genera. * 



