172 BRITISH FISH AND FISHERIES. 



fishes, and the gill-aperture is merely a small 

 fissure, and the ribs are rudimentary. In some, 

 as the globe-fishes, or diodons, tetraodons, etc., 

 there are no true teeth, but the jaws are armed 

 with a substance like ivory, resembling in form 

 a parrot's beak, but of laminated structure. 

 These successive layers succeed each other in 

 proportion, as the more anterior are worn by 

 the effect of crushing and grinding the sea- 

 weeds and crustaceous animals on which they 

 feed. 



In another family, containing the file-fishes, 

 (Batistes,} and the box-fishes, (Ostracion,) the 

 muzzle is produced and conical, with a small 

 mouth, armed with distinct, but not numerous 

 teeth in each jaw. Some of these fishes feed 

 on corals and sea-weed. 



There are three instances on record of a 

 species of globe-fish (Pennant's globe-fish) 

 having been taken on the coast of Cornwall, 

 wanderers by accident from warmer latitudes. 

 A species of file-fish has once been taken off 

 the Sussex coast. 



Two species of sun-fish are occasionally seen 

 off our coasts, of which the short sun-fish 

 ( Orthagoriscus mold) is the most common. This 

 fish is of a circular form, and though there is a 

 caudal fin, united to the dorsal fin and the 



