Xiphias (the Sword-fish) has occurred on the English coast.
Family 19.—GOBIIDÆ. (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 temperate 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, Latrunculus, 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, 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.
Family 21.—OXUDERCIDÆ. (1 Genus, 1 Species.)
"A marine fish, with an elongate sub-cylindrical body and no ventral fins."