212 FISHES. 



f f Skin with conical tubercles; teeth villiform; dorsal I 4; 

 the spine tentacle -like, retractile into a cavity beneath a 

 prominent protuberance on forehead. 



Maltheidw, the Sea Bats. 

 ** Head high, compressed ; teeth card-like. 



Antennariidce, the Diablos. 



FAMILIES OF PLECTOGNATHI. 



*jjaws modified into a sort of beak, without distinct teeth, 

 f Both jaws divided by a median suture (teeth fused into two 

 in each jaw); belly greatly inflatable. 



Tetorodontidcs, the Puffers. 



f f Jaws without median suture ; belly scarcely or not inflatable. 



\ Body scarcely compressed, spinous, with a distinct caudal 



fin. .... Itiodontida, the Sox Fishes. 



\\ Body much compressed, very short, truncate ; the vertical 



fins more or less confluent. 



Orthagoriscidce, the Globe Fishes. 

 ** Jaws with distinct teeth. 

 a. Front teeth incisor-like ; 1 to 3 dorsal spines ; no carapace. 



Balistidw, the File Fishes. 



aa. Teeth slender ; no dorsal spines ; body enveloped in a box- 

 like carapace, formed of hexagonal bony plates; snout, 

 bases of fins and tail free, covered with skin. 



Ostraciontidce, the Trunk Fishes. 



FAMILIES OF LOPHOBRANCHII. 



* Tail prehensile, without caudal fin ; body abruptly contracted 



at base of tail ; head crested, out of line of axis of body. 



Hippocampidai, the Sea Horses. 



** Tail not prehensile, with a developed caudal ; body gradually 

 tapering; direction of head in a line with axis of body. 



Syngnathida, the Pipe Fishes. 



ORDERS OF GANOIDEI. 



* Skeleton bony; body scaly; air bladder cellular, lunglike 



(HYOGANOIDEI). 

 f Scales cycloid ; snout short, broad. . CYCLOGASOIDEI, CC. 



