Order I.—ACANTHOPTERYGII.
Family 1.—GASTEROSTEIDÆ. (1 Genus, 11 Species.)
"Fresh-water or marine scaleless fishes, with elongate compressed bodies and with isolated spines before the dorsal fin."
Distribution.—Palæarctic and Nearctic regions.
The species of Gasterosteus, commonly called Sticklebacks, are found in rivers, lakes, estuaries, and seas, as far south as Italy and Ohio. Four species occur in Britain.
Family 2.—BERYCIDÆ. (10 Genera, 55 Species.)
"Marine fishes, with elevated compressed bodies covered with toothed scales, and large eyes."
Distribution.—Tropical and temperate seas of both hemispheres.
Their northern limit is the Mediterranean and Japan. Most abundant in the Malayan seas.
Family 3.—PERCIDÆ. (61 Genera, 476 Species.)