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GEOGRAPHICAL ZOOLOGY. 
[part iv. 
Family 18. — XIPHIIDiE. (2 Genera, 8 Species.) 
(i 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. — GOBIIDiE. (24 Genera, 294 Species.) 
K 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 - 
cuius , and Callionymus occur in Britain. Several genera are 
confined to the East Indian seas and rivers, but none seem 
peculiar to America. The genus Periopthalrmis consists of the 
curious, large-headed, projecting-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 (Cyclopterus and Liparis) occur in 
British seas. 
