Div. III. BONY Fish, includes those whose muscles are supported by bones or spines, which breathe thro' gills covered or guarded by thin bony plates, open on the side, and dilatable by means of a certain row of bones on their lower part, each separated by a thin web; which bones are called the radii branchiostegi, or the gill-covering rays. The tails of all the fish that form this division are placed in a situation perpendicular to the body; and this is an invariable character.
The great sections of the Bony Fish into Apodal, Thoracic, Jugular, and Abdominal, he copies from Linnaeus: who founds this system on a comparison of the ventral fins to the feet of land-animals or reptiles; and either from the want of them, or their particular situation in respect to the other fins, establishes his sections.—In order to render them perfectly intelligible, it is necessary to refer to those several organs of movement, and some other parts, in a perfect fish, or one taken out of the three last sections. In fig. 4. (the Haddock), a, is the pectoral fins; b, ventral fins; c, anal fins; d, caudal fin, or the tail; e, e, e, dorsal fins; f, bony plates that cover the gills; g, branchiostegous rays and their membranes; h, lateral or side line.
SECT. 1. APODAL: The most imperfect, wanting the ventral fins; illustrated by the Conger, fig. 3. This also expresses the union of the dorsal and anal fins with the tail, as is found in some few fish.—Genera: The Eel, Wolf-fish, Lance, Morris, Sword-fish.
SECT. 2. JUGULAR: The ventral fins b, placed before the pectoral fins a, as in the Haddock, fig. 4.—Genera: The Dragonet, Weever, Codfish, Blenny.
SECT. 3. THORACIC: The ventral fins a, placed beneath the pectoral fins b, as in the Father Lasher, fig. 5.—Genera: The Goby, Bull-head, Doree, Flounder, Gilt-head, Wrass, Perch, Stickleback, Mackerel, Surmullet, Gurnard.
SECT. 4. ABDOMINAL: The ventral fins placed behind the pectoral fins, as in the Minow, fig. 6.—Genera: The Loche, Salmon, Pike, Argentine, Athrine, Mullet, Flying-fish, Herring, Carp.