194 CLASSIFICATION OF FISHES, ETC. 



Tetrosomus. Body quadrangular ; spines on the back and 



belly. 



* Body triangular. 



Flatycanthus. Bod}- with several flattened bony obtuse spines. 

 Ijactophrys. Front and vent with two horn-like acute spines. 

 Ehinesonius. Body without spines, often scored as in the Balistin^. 



2. Sub-family Balistin^. — Body granulated or reticulated ; 



muzzle produced. 



Balistes. Body reticulated; sides of the tail armed with 



spines. 



Balistes. The first dorsal spine smooth, acute ; caudal rounded. 

 Rhinecanthus. First dorsal spine thick, rough, obtuse ; caudal rounded. 

 Melichthys. Pelvis without rays ; caudal fin doubly lunate. 

 Canthidermes. Body covered with prickles ; caudal fin rounded. 



Capb.iscus. Body reticulated ; sides of the tail without spines, 



Capriscus. Caudal fin truncate or rounded ; pelvis without rays. 



Leiurus. Pelvis forming a large and distinctly rayed ventral fin ; rays 

 greatly lengthened; caudal small, doubly lunated. 



Ckalisomus. Caudal fin doubly lunated ; pelvis with small rays; dor- 

 sal spine obtuse : dorsal and anal fins falcated. 



Zenodon. Two longer pointed teeth in the upper jaw ; tail singly lu- 

 nated; pelvis without rays, nearly concealed ; dorsal 

 spine obtuse, truncate. 



PachyrMthus. Body short, compressed, triangular; head very large 

 and long ; eyes just above the pectoral fin ; two front 

 teeth in each jaw very long ; dorsal and anal of 

 equal breadth ; caudal doubly lunate. 



MoxACANTHus. The first dorsal fin represented by a single 



ray. 



Alutera. Pelvis concealed beneath the skin ; tail smooth. 

 Monacanthus. Body granulated ; pelvis prominent ; tail spined. 

 Cantherhines. Body granulated ; pelvis prominent ; tail smooth. 

 Chietoderma. Body covered with prickles ; tail smooth. 

 Trichoderma. Body reticulated ; sides of the tail with bristles and 

 spines. 



TRIACA^'THUs. Ventral fins formed of two spines, 

 PsiLOCEPHALUS. Body linear ; head very long ; mouth ver- 

 tical, bearded. 



3. Sub-family Tetraodin^. — Body oblong; prickly. 



Tetraodon. Head short ; body covered with prickles. 

 Leiodon. Head short ; body entirely smooth. 

 Lagocephalus. Body above smooth ; belly armed with spines. 

 Cirrhisomus Sides of the body with cirriform appendages. 

 Canthigaster. Muzzle prolonged and narrow ; belly with spines. 



4. Sub-family DioDoxiN^. — No true teeth; body orbicular, 



armed with spines. 



Triodon. Belly forming an enormous sack ; body with short prickles. 

 Diodotu Margins of the jaws undivided ; spines long. 



