SYNOPSIS OF THE ARRANGEMENT OF FISHES. 175 



3. Sub-family Xiphian^. Jaws greatly produced, sword- 



shaped, the upper longest. 



XiPHiAS. Ventral fins wanting. 



Tetrapterus. Ventrals formed of a single bony ray. 

 HisTioPHORUs. Ventrals of two connected rays. 

 Zanclcrus Sw, Scales hard, oblong ; ventrals of two long 



equal rays. 

 Mach^ra. No ventrals ; snout short. 



4. Sub-family Alefisaurikje. — Body long, linear, thin; a 



second adipose fin. 



Alepisaures. Lower jaw long; chin pointed; first dorsal 

 very high, 



5. Sub-family Fistularin^e. — Jaws excessively lengthened ; 



mouth terminal. 



FisTULARiA. Body smooth ; without spines on the back. 



Family 2. ZEID^. 



Body either oval or rhomboid ; scales often conspicuous ; back 

 spined ; strong anal spines. 



1. Sub- family MASTECEMSLiNiE. — Body somewhat anguil- 



liform; snout produced. 



Rhynchobdella. Dorsal and anal separate from the caudal. 

 Mastecemblus. Dorsal, caudal, and anal fins united. 

 NoxocANTHUs. A TOW of spines representing the dorsal fin. 



2. Sub-family Aulostomin^. — Lateral line mailed, or the 



jaws very long. 



AuLosTOMA. Jaws very long, tubular ; lateral line smooth. 

 Polycanthus. Jaws long ; lateral line carinatedj body five-sided, j 



Gasterosteus. Sides of the body with imbricate plates. 

 Leiurus. Sides of the body smooth. 



3. Sub-family Sph^rin^ Body long ; dorsal fins two, 



remote ; lower jaw longest. 



Sph^rina. Body anguilliform ; lower jaw longest, pointed ; 



teeth large. 

 Atherina. Mouth obliquely vertical ; head very obtuse. 



