238 FISHES. 



DIVISION I. OSSEOUS FISHES. 

 SPINY-FINNED FISHES. ORDER ACANTHOPTERYGIL* 



In the Spiny-finncd fishes, the first fin-rays of the back arc 

 always bony and spinous. When there are two dorsal fins, these 

 spiny rays only exist in the front one, and when there is but one, 

 they sustain at least its anterior portion, or sometimes are entirely 

 free and separate. Generally there is also a bony ray to each 

 ventral fin, and frequently the anal fin has some of its front rays 

 spinous. 



~ IG. 246. THE PKRCH. 



This Order may be divided into several families, the most re 

 niarkable of which are the Perches y the Mullets, the Gurnards, 

 the Labyrinthiform Pharyngeals, and the Mackerels. 



The family of Perches (Pcrcoidsfi or fishes that resemble the 



* 8,Kav6a, acantha, a thorn or spine; irreptyiov, pterygion, a fin: having fins with 

 spinous or thorn-like rays. 



t The families of fishes are frequently designated by adding the syllable aid derived 

 from the Greek word et'56s (eidos), form to the name of the typical species. Thus, 

 Percoid, means like the Perch ; Gadoid, like the Cod ; Scomberoid, like the Mackerel, 

 &c. In the same way, the Greek patronymic ida; is frequently employed : thus we say, 

 Perca, the Perch; Percidse, the family of Perches ; GaduS, the Cod; Gadidse, 

 the family of Cod-fishes ; Scpmber, the Mackerel; Scomberidae, the family of 

 the Mackerels. In the following pages both these forms are used indiscriminately. 



