1S2 Mr. G. A. Boulenger on (he Suborders and 



II. Prsemaxillaries not protractile ; scales usually small or ab=ent ; body 

 more or less elongate ; dorsal tin 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. Scombrida. 



Vertebras without transverse processes ; soft dorsal 

 fin shorter than the spinous, if the latter be 



distinct ; pectoral fin low down the sides 4. Triehivrida. 



Vertebrae without transverse processes ; snout pro- 

 duced into a spear 5. Histiophoridce. 



Vertebrae with transverse processes bearing the 

 ribs ; snout produced into a sword ; no 



ventrals C. XijJiiida. 



Vertebra without transverse processes ; gill- 

 membranes attached to isthmus ; dorsal and 

 anal fins formed of unarticulattd, widely set 



rays ; dentition very feeble 7. Luvarida. 



B. Pseudobranchiae absent ; no well-developed transverse processes 

 to the praecaudal vertebrae, the ribs and the epipleui als inserted 

 close together on the centra ; snout short and very deep. 



8. Coryphcenidcr. 



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

 large ; dorsal and anal fins elongate, without distinct spinous 

 division ; most of the praecaudal vertebras with strong haema- 

 pophyses, to which the ribs are attached. ... 9. Bramidce. 



Division III. Zeorhombi. 



Aberrant, strongly compressed Perciformes, with very 

 short praecaudal region, modified in the direction of the flat- 

 fishes, culminating in asymmetrical forms, and characteriz3d 

 "by the combination of an increased number (7 to 9) of 

 ventral rays, with absence of hypural spine (by which the 

 Beryciclse are excluded), or by asymmetry of the skull in 

 the forms in which the spine of the ventral fin has been lost. 

 Among the symmetrical forms, the existing Zeidse agree 

 with the Berycidie in having more than five soft rays to the 

 ventral fins, and are probably derived, together with the 

 Eocene Amphistiidaa, from some common ancestral group 

 still to be discovered in Cretaceous beds. These Zeidse have 

 much in common with the Pleuronectidai * and might be 

 regarded as forming part of the family out of which the 

 latter have sprung, were it not that they have lost the last 

 half-gill. Aivphistium is probably more nearly related to 

 the Pleuronectidaj, which may have been directly derived 

 from the family of which it is as yet the only known 

 representative f« 



* C/. Thilo, Zool. Anz. 1902, p. 305. 



T Cf, Bouler^r, Ann. & Mag. Nat. Hist. {7) x. 1902, p. 295, 



