Synopsis of the Families
I. Praemaxillaries more or less protractile, not beak-like; scales small or absent, sometimes with enlarged lateral scutes; spinous dorsal fin short or replaced by a series of isolated spines; anal usually with one or two spines detached from the rest of the fin.
Praecaudal vertebrae with transverse processes behind which the ribs are attached .......... 1. Carangidae.
Praecaudal vertebrae without well-developed parapophyses, ribs and epipleurals inserted close together on the centra .......... 2. Rhachicentridae.
II. Praemaxillaries not protractile; scales usually small or absent; body more or less elongate; dorsal fin elongate, single or divided, without free spines; no free anal spines.
A. Pseudobranchiae present.
Vertebrae without transverse processes; soft dorsal fin longer than the spinous; pectoral fins high up the sides .......... 3. Scombridae.
Vertebrae without transverse processes; soft dorsal fin shorter than the spinous, if the latter be distinct; pectoral fins low down the sides .......... 4. Trichiuridae.
Vertebrae without transverse processes; snout produced into a spear .......... 5. Histiophoridae.
Vertebrae with transverse processes bearing the ribs; snout produced into a sword; no ventrals .......... 6. Xiphiidae.