PERCESOCES 637 



Ribs mostly sessile ; lower pharyngeal boaes distinct ; pectoral fins nearer 

 the ventral than the dorsal line . . .2. Aminodytidae. 



II. Veiitral fins, if present, more or less approximated to the pectorals. 



A. Two well-developed dorsal fins, the anterior small and formed, 



at least in part, of spinons rays. 



1. Ribs attached to sti'ong parapophyses. 



Pelvic bones free or connected with tlie clavicles by ligament ; pectoral fins 

 inserted high np . . . . . .3. Atherinidae. 



Pelvic bones suspended from the po.stclavicles ; pectoral fins inserted very 

 high up ; teeth very feeble or absent . . 4. Mugilidae. 



Pelvic bones suspended from the postclavicles ; pectoral fins low down, 

 with detached lower rays . . . . 5. Polynemidae. 



Pelvic bones connected with the clavicles by ligament ; pectoral fins nearer 

 the ventral than the dorsal line ; dentition powerful, cardiform ; scales 

 minute or absent ...... 6. Chiasmodontidae. 



2. Anterior ribs sessile ; pelvic bones not connected with the 



scapular arch ; pectoral fins nearer the ventral than the 

 dorsal line . . . .7. Sphyraenidae. 



B. Spinous dorsal, if present, connected with the soft. 



1. Anterior vertebrae without parapophyses ; scales on head, if 



present, small. 

 Oesophagus with lateral sacs whicli are beset witli papillae internally ; 

 spinous dorsal long ; scales rhomboidal, in oblique transverse series ; pelvic 

 bones free ....... 8. Tetragonuridae. 



Oesophagus with lateral sacs which are beset with toothed papillae internally; 

 spinous dorsal, if distinct, shorter than the soft dorsal ; scales moderate or 

 small, cycloid, often deciduous. . . .9. Stromateidae. 



No sacs in the oesophagus ; fins without spines ; scales very small or absent 



10. Icosteidae. 



2. All, or all but the anterior two vertebrae with parapophyses ; 



scales on head large ; a superbranchial cavity. 

 No spines to the fins . . . . H- Ophiocephalidae. 



Strong spines to the dorsal, anal, and ventral fins 12. Anabantidae. 



Fam. 1. Scombresocidae. — Maxillary entering the border 

 of the upper jaw ; dentition moderately strong or feeble. Lower 

 pharyngeal bones united. Praecaudal vertebrae with strong 

 parapophyses supporting the ribs. Body covered with cycloid 

 scales. Pectoral fins inserted very high up ; ventral fins widely 

 separated from the pectorals, without spines, with 6 rays. Dorsal 

 fin opposed to the anal, and likewise formed entirely of soft rays. 

 Air-bladder generally present, sometimes cellular. 



The shape of the head and body vary greatly, and the pectoral 

 fin may reach an extraordinary wing -like development. The 

 dorsal fin may be followed by a series of finlets, as in many of 

 the Scombridae. Most of the Scombresocidae, of which about 

 200 species are known, are marine ; some are carnivorous, 



