CLASS IV. ORDER V, 89 



ORDER 5. BRANCHIOSTEGUS. 



Skeleton cartilaginous , without ribs ; gill-mem- 

 tranes, with or without gill-covers. 



LOPIIIUS, (angler,) head depressed ; teeth nu- 

 merous, sharp ; tongue armed with teeth ; pecto- 

 ral fins brachiated ; no gill covers. 



CYCLOPTERUS, (sucker,) head obtuse ; teeth in 

 the jaws ; tongue short and thick; body thick 

 without scales ; ventral fins united into a circle. 



BALISTES, (file-fish,) teeth several in both jaws; 

 body compressed ; abdomen cariuated ; skin 

 tough, often reticulated by scale-like divisions ; 

 no gill-covers, 



OSTRACION, (trunk-fish,) teeth pointing for- 

 ward, cylindric, rather blunt ; body mailed by a 

 bony covering. 



DIODON, jaws bony, undivided ; body beset 

 with moveable spines. 



CEPHALUS, (mullet, sun-fish,) jaws bony ; bo- 

 dy terminating abruptly, so that the whole fish 

 resembles the head of a fish. 



TETRODON, (sun fish, &c.) jaws bony, divided 

 at the tip ; body roughened beneath ; ventral fins 

 wanting. 



SYGNATHUS, (pipe-fish,) snout sub-cylindric, 

 with terminal mouth ; body lengthened, jointed, 

 mailed ; ventral fins none. 



CENTRISCUS, snout lengthened; body compress- 

 ed, carinated beneath ; ventral fins united. 



CHIMERA, (sea-inonster,) head pointed on tho 

 upper part, mouth placed beneath, with the upper 

 lip five-cleft ; no gill-covers j two incisors in front 

 above and below. 



