212 FISHES. 



ff Skin with conical tubercles; teeth villiform; dorsal I — 4; 

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

 prominent protuberance on forehead. 



MaltheidcB, the Sea Bats. 



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



Aiiteiinariidce, the Diablos. 



FAMILIES OF PLECTOGNATHI. 



* Jaws 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. 



TetrodontidcB, the Puffers. 



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



I Body scarcely compressed, spinous, with a distinct caudal 

 fin. .... Diodontidce, the Box Fishes. 



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

 fins more or less confluent. 



Orthagoriscidm, the Globe Fishes. 

 ** Jaws with distinct teeth. 



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



BaUstidcc, 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. 



Hippoeampidiv, the Sea Horses. 



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

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



Syngnathidce^ the Pipe Fishes. 



ORDERS OF GANOIDEI. 



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



(Hygganoidei). 



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



