206 FISHES. 



** Dorsal fin single, not divided to its base. 

 k. Fresh water species. 



1. Ventrals I, 5 ; dorsal spines 5 to 12 ; vent normal. B. 6. 

 m. Teeth on vomer ; anal spines 3 to 9. CENTRAKCHID^;, 92. 

 mm. No teeth on vomer; anal with 2 (or 1) spines, the 

 second very strong. . . . ' SCI/EXID^E, 94. 

 mmm. No teeth on vomer; no lateral line; dorsal with 

 five spines ; anal with three. , ELASSOMID^;, 92 (b). 

 II. Ventrals 7-rayed ; dorsal spines 3 ; vent jugular. 



APHODODERHXae, 93. 



kk. Marine species. 



1. Cheeks mailed (as in Cottidce, etc.) 



n. Body covered with bony, keeled plates; no dorsal 

 spines. . . . Agonidce, the Sea Poachers. 



nn. Body with ordinary scales ; spinous dorsal many- 

 rayed. . . Scorpcenidce, the Sea Scorpions. 



2. With broad, cutting, incisor -like front teeth, or with 



crushing, molar-like lateral teeth or both ; scales rather 

 large ; usually a recumbent free spine in front of the 

 dorsal fin ; lower pharyngeals not united. 

 o. Opercular bones entire ; vertical fins not much scaly. 



Sparidce, the Sea Breams. 



oo. Preopercle denticulated ; soft parts of vertical fins 

 densely scaly. . Pimelepteridcn, the Fat-Fins. 

 2. Body much compressed and elevated; the soft rays of the 

 vertical fins covered high up with ctenoid scales ; teeth 

 villiform; body often dark-banded. 

 p. Dorsal with less than 10 spines, separated by a notch 

 from the soft part ; spinous dorsal scaleless. 



Ephippida, the Moon Fishes. 



pp. Dorsal undivided, with 10 or more spines, scaly 

 throughout; fins often filamentous. 



Chcetodontida, the Chatodonts. 



4. Ventrals wanting ; scales minute ; body high, much 



compressed. . Stromateidce, the Harvest Fishes. 



5. Ventrals jugular, few-rayed or wanting; body long and 



low ; dorsal fin very long, occupying most of the back, 

 at least half of it and sometimes all composed of flexible 

 spines ; scales small or none : usually an anal papilla. 



