428 TELEOSTEI 



Family PEMPHERIDAE. The soft pelvic rays are reduced to five. 

 Baihydupea preserves the open pneumatic duct, has no median spines, 

 and has subjugular pelvic fins. The family's systematic position is very 

 doubtful. 



Pempheris, C. and V. (Fig. 433) ; Bathyclupea, Ale. ; Parapriacanthus, 

 Steind. tropical seas. 



Family MOXOCENTRIDAE. The snout is very obtuse, the ribs are lost 



FIG. 434. 

 Monocentris japonicus, Htt. (After Giinther.) 



on the first half-dozen vertebrae, only two or three soft dermal rays 

 remain on the pelvic fin, and the scales are closely set in a rigid armour. 

 Monocentris, Sch. (Fig. 434) ; Indo-Pacific. 



Subdivision 2. 



This is founded chiefly on the structure of the pelvic fins. If 

 the persistent occurrence of one spine and not more than five 

 jointed 'soft' dermal rays in these fins is of any phylogenetic 

 significance, all or some of these families must have been derived 

 from a common ancestor which branched off from the Beryciform 

 stock. 



TRIBE 1. PERCIFORMES. 



Spines are usually well developed, and the pelvic fins are thoracic 

 and provided with one spine and four or five jointed rays. The subocular 

 shelf is not always present ; it is an ingrowth, from one or more of the 

 suborbitals, supporting the eyeball (Fig. 436, B). The pectoral radials 

 are generally flattened and expanded at each end. It is scarcely possible 

 as yet to attempt to group phylogenetically the numerous families included 

 in this Tribe. 



SUB-TRIBE A. I. With a subocular shelf (Fig. 436, B). 



Family SPARIDAE. The Sea -Breams, are deep -bodied fish, with a 



