The Geographical Distribution of Animals, Volume 2 / With a study of the relations of living and extinct faunas as elucidating the past changes of the Earth's surface

by Alfred Russel Wallace

Distribution.—Coasts and fresh waters of temperate regions of both hemispheres. Three species of Petromyzon (Lampreys), are British.

Family 115.—MYXINIDÆ. (2 Genera, 5 Species.)

"Marine eel-like fishes, with four pairs of barbels."

Distribution.—Seas of the temperate regions of both hemispheres.

Sub-class VI.—LEPTOCARDII.

Family 116.—CIRRHOSTOMI. (1 Genus, 1 Species.)

"A small marine fish with no jaws or fins, and with rudimentary eyes."

Distribution.—The only species, the Lancelet (Amphioxus), is the lowest form of living vertebrate. It is found in the temperate regions of both hemispheres, and has occurred on our southern coast.

Remarks on the Distribution of Fishes.

Marine Fish.—There are about 80 families of marine fishes, and of these no less than 50 are universally, or almost universally, distributed over the seas and oceans of the globe. Of the remainder many are widely distributed, some species even ranging from the North Atlantic to Australia. Six families are confined to the Northern Seas, but four of these consist of single species only, the other two being the Discoboli (2 genera, 11 sp.), and the Accipenseridæ (2 genera and 20 sp.). Only one family (Acanthoclinidæ) is confined to the Southern oceans, and that consists of but a single species. Four families (Sternoptychidæ, Stomiatidæ, Alepocephalidæ and Halosauridæ) are confined to the Atlantic Ocean, while 13 are found only in the Pacific; and of the remainder several are more abundant in the Pacific than the Atlantic. Two families (Lycodidæ and Gadidæ) are found in the Arctic and Antarctic seas only, though the latter family has a single species in the Indian seas. Among the curiosities of distribution are,—the extensive genus Diagramma, confined to the Pacific with the exception of one species in the Mediterranean; the single species constituting the family Lophotidæ, found only in the Mediterranean and Japan; the small family of Notacanthi, confined to Greenland, the Mediterranean, and West Australia; and the four families, Sternoptychidæ, Stomiatidæ, Alepocephalidæ, and Halosauridæ, which are believed to inhabit exclusively the depths of the ocean, and are therefore very rarely obtained.