ACANTHOPTERYGIOLTS FISHES. 
20S 
ua. Two dorsal fins. 
b. Head armed, 
c. Head armed with spines. 
d. Ventrals thoracic. 
Perea. 
Sciaena. 
dd. Ventrals jugular. 
Trachinus. 
JLophius. 
cc. Head armed with a coat of mail, by the extension of 
the suborbital bone ; gill lid spinous. 
Trigla. 
Cataphractus. 
Cottus. 
bb. Head without armature. 
c. Ventral fins thoracic. 
Mullus. 
cc. Ventral fins abdominaL 
Mugil. 
Atherina. 
Sect. VI. Scales small., often scarcely perceptible., unless at the extremity of the 
lateral line., where they sometimes form a ridge. In other cases 
this ridge is formed by a protuberance of the skin., supported by 
transverse processes, 
a. Two dorsal fins. 
b. The first dorsal fin entire. 
Scomber. 
Trachurus. 
Zeus. 
bb. Spines of the first dorsal fin without a connecting mem- 
brane. Ventrals consisting of a single spine each. 
Spinachia. 
Gasterosteus. 
aa. One dorsal fin, elevated at its origin and termination. No 
teeth. 
Lampris. 
Xiphias. 
VII. Mouth tubular. 
Centriscus, 
