430 GEOGRAPHICAL ZOOLOGY. [part iv. 



Family 18.— XTPHIID^. (2 Genera, 8 Species.) 



" Marine fishes, with elongate compressed body and a produced 

 sword-shaped upper jaw." 



Distribution. — Mediterranean, and open seas between or near 

 the Tropics. 



Xiphias (the Sword-fish) has occurred on the English coast. 



Family 19.— GOBIID^. (24 Genera, 294 Species.) 



*' Carnivorous fishes, with elongate low, naked, or scaly bodies, 

 living at the bottom of the shallow seas or fresh waters of tem- 

 perate or tropical regions. Individuals of the same species often 

 differ in inhabiting exclusively fresh or salt water. 



Distribution. — All temperate and tropical regions, from 

 Scotland and Japan to New Zealand. Species of Gobius, Latrun- 

 culus, and Callionymus occur in Britain. Several genera are 

 confined to the East Indian seas and rivers, but none seem 

 peculiar to America. The genus Periopthalmus consists of the 

 curious, large-headed, projectiug-eyed fishes, so abundant on the 

 muddy shores of African and Eastern tidal rivers, and which seem 

 to spend most of their time out of water, hunting after insects, &c. 



Family 20.— DISCOBOLI. (2 Genera, 11 Species.) 



" Carnivorous fishes, with oblong naked or tubercular bodies, 

 living at the bottom of shallow seas, and attaching themselves 

 to rocks by means of a ventral disc. 



Distribution. — All northern seas, as far south as Belgium, 

 England, and San Francisco. 



Species of both genera {Cydopterus and Liparis) occur in 

 British seas. 



