676 TELEOSTEI 



CHAP. 



regards external features, it may be stated that the dorsal and anal 

 spines, if present, are either weak and slender, or, if strong, short 

 and detached ; the caudal peduncle is constricted, and the caudal 

 fin, if well developed, is usually deeply forked, and with the 

 forked bases of the very numerous rays much longer than in 

 most of the Perciformes, embracing at least a considerable portion 

 of the expanded hypural bones, a character by which the Chaeto- 

 dontidae, Acanthuridae, and several extinct types which have 

 been placed with the Carangidae are at once excluded. All are 

 carnivorous and marine, and many are pelagic and of very wide 

 distribution. No praetertiary members of this division, as here 

 defined, have yet been found. 



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 Avhich 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. 



Vertebrae without transverse processes ; gill-membranes attached to 

 isthmus ; dorsal and anal fins formed of unarticulated, widely set 

 rays ; dentition very feeble . . . .7. Luvaridae. 



B. Pseudobranchiae absent ; no well-developed transverse processes to the 

 praecaudal vertebrae; the ribs and the epipleurals inserted close 

 together on the centra ; snout short and very deep 8. Coryphaenidae. 



III. Praemaxillaries not protractile, or if slightly protractile, scales large ; 

 dorsal and anal fins elongate, without distinct spinous division ; most of the 

 praecaudal vertebrae with strong haemapophyses, to which the ribs are 

 attached . 9. Bramidae. 



