CHAP. XXIII 



ACANTHOPTERVGII 



651 



o 



a: 

 I— 



CO 



O 



3 



u 



Q 

 LU 



a. 



< 



CO 



□ 



I— 



LU 



OpJudiidae 



SCLEROPARE/ 



D/SCOCEPmU 

 -Bcdrac/iid/id 



'tOBJ/fORMES 

 JUCUl'ARES 



r/EN/OSOM/ 



SCOMBR/fORMES 

 Scfiridx 



WRT/FORMES 



SernUd^'^^^'^-^ ZEORROMB/ 



jBciycidiJe 



fL 

 O 

 X 



< 



u 



Feg. 399.- 



HAPLOIVII 



-Diagram showing probable relationship of the various groups to one 

 another. 



Primary shoulder-girdle composed of a perforate scapula and a coracoid ; of 



the four or five pterygials, or basal bones of the pectoral fins, only one or 



two are in contact with the coracoid ; ventral fins thoracic. 



Rays of the caudal fin not strongly forked at the base ; hypural usually^ 



with a basal spine or knob-like process on each side ; epipleural bones 



usually inserted on the parapophyses or on the ribs ; dorsal fin usually 



with strong spines ; caudal peduncle rarely much constricted 



I. Percifobmes. 

 Rays of the caudal fin strongly forked at the base, embracing a consideraljle 

 portion of the hypural, which alwaj'S bears a basal spine ; epipleural bones 

 usually inserted on the centra or on the parapophyses, rarely on the ribs ; 

 dorsal spines feeble or detached ; caudal peduncle much constricted ; 

 scales usually very small or absent . . II. Scombrifohmes. 



