OSSEOUS FISHES. 9t 



LESSON VI. 



ORDER OF ACANTHOPTERYGIANS. Family of Percoides, (Perches, 

 Rock-Jish.) Family of Mulloides, (Red Mullets, Flying-fishes.) 

 Family of Mailed- cheeks. Family of Scienoides. Family 

 of Sparoides. Family of Menides. Family of Syuamipennes. 

 Family of Labyrinthiform pharyngeals. Family of Scorn- 

 beroides, (Mackerel. Mackerel Fishery. Tunny. Sword~ 

 Fish, c.) 



DIVISION OF OSSEOUS FISHES. 

 ORDER OF AC ANTHOPTE R YGII. 



1. The Order of Acanthopterygians is easily recognised by the 

 disposition of the branchia3 and upper jaw, and by the spinous 

 fins. Three fourths of the fishes known, belong to this group ; 

 but these animals resemble each other in so very many respects, 

 that in spite of the numerous differences we remark among them, 

 we can only separate them into several natural families, all of 

 which we are obliged to place in the same order 



2. The first fin-rays of the back are always bony and spinous, 

 (Fig. 46.) When there are two dorsal fins, these spinous rays 

 only sustain the first; and p^ 45 



when there is but one of 

 these organs, they sustain at 

 least its anterior portion; 

 and we sometimes find them 

 entirely free or separate. 

 Generally there is also a 

 bony ray to each ventral 

 fin, and frequently the anal 

 fin has some spines for its first rays. 



3. This order is divided into six natural families, the most 

 remarkable of which are, the Percoides, the Mulloides, the Mailed- 

 cheeks, the Labyrinthiform Pharyngeals and Scomberoides. 



4. The FAMILY OF PERCOIDES, (or fishes that resemble a Perch) 

 is composed of fishes that have an obtong, more or less com- 

 pressed body, covered with scales, which are generally hard ; 

 the mouth large, and armed with teeth, situate upon the front of 

 the vomer, and almost always on the palate bones as well as thfe 

 jaws, the branchial arches and pharyngeal bones ; the operculum, 

 or the bone situate immediately anterior to it, and therefore called 

 pre-operculum, or ante-operculum, is dentate or spiny on its edge ; 



1. How is the Order of Acanthopterygians distinguished ? 



2. What is the character of their dorsal fins ? 



3. How is this order divided ? 



