History of British animals - University of Guam Marine Laboratory

ACANTHOPTERYGIOUS FISHES.f203aa.Two dorsal fins.b. Head armed.bb.c. Head armed with spines.d. Ventrals thoracic.Perca.Sciaena.dd. Ventrals jugular.Trachinus.Lophius.cc. Head armed with a coat of mail, by the extension ofthe suborbital bone :gill lid spinous.Trigla.Cataphractus.Cottus.Head without armature.c. Ventral fins thoracicMullus.cc.Ventral fins abdominal.Mugil.Atherina.Sect. VI. Scales small, often scarcely perceptible, unless at the extremity of thelateral line, where they sometimes form a ridge. In other casesthis ridge is formed by a protuberance of tlie skin, supported bytransverse processes,a. Two dorsal fins.b. The first dorsal fin entire.Scomber.Trachurus.Zeus.bb.Spines of the first dorsal fin without a connecting membrane.Ventrals consisting of a single spine each.Spinachia.Gasterosteus.aa. One dorsal fin, elevated at its origin and termination. Noteeth.VII. Mouth tubular.Centriscus.Lampris.Xiphias.