588 PROCEEDINGS OF THE NATIONAL MU8EUBI. vol.41. 



has been confused with Sparus lotus under the name of schlegeli and 

 with Sparus longispinis from India, but it is distinct from both, 

 and it is not yet recorded from the East Indies. 

 (Named for Mr. R. Swinhoe, consul at Chifu.) 



7. Family KYPHOSID^. 



The RUDDER FISHES. 



Herbivorous fishes, with incisor teeth only in the front of the jaws. 

 Body oblong or elevated, with moderate or small scales, ctenoid or 

 smooth. Mouth moderate, with incisor-like teeth in the front of each 

 jaw; no molars; teeth on vomer and palatmes present or absent; 

 premaxillaries moderately protractile; preorbital rather narrow, 

 sheathing the maxillary. Gill rakers moderate; pseudobranchise 

 well developed; opercles entire. Gills 4, a slit behind the fourth; 

 gill membranes separate, free from the isthmus; dorsal fin continuous 

 or divided, with 10 to 15 rather strong spines, the soft dorsal naked 

 or scaly; anal with 3 spines; ventrals thoracic, the rays I, 5, an 

 accessory scale at base; caudal lunate or forked; pectoral fin with 

 all its rays branched. Intestinal canal elongate, with few or many 

 pyloric caeca. Air bladder usually with 2 posterior horns. Verte- 

 brae in ordinary or slightly increased number, 24 to 28. Post-tem- 

 poral of normal percoid form, the stout forks not adnate to the cra- 

 nium. Herbivorous shore fishes, feeding largely on green or olive 

 algse; chiefly of the Mediterranean Sea and the Pacific Ocean; most 

 of them valued as food. 



Key to genera. 



a'. GiRELLiNiE. Soft part of doraal and anal fins naked or partly scaled; head more 

 or less naked; teeth in broad bands, all freely movable, none on vomer; pyloric 

 caeca very numerous; vertebrae in somewhat increased number. Pacific Ocean. 

 b}. Incisors all tricuspid. 

 c^ Dorsal spines 14 or 15; each jaw with a series of flat, movable, tricuspid in- 

 cisors, behind which ia a broad band of similar smaller ones; dorsal continu- 

 ous, its spines low Girella, 18. 



a 2. Kyphosin.e. Soft parts of vertical fins closely scaled; teeth more or less fixed, 

 usually present on vomer, pyloric caeca numerous. 



(i '. Top of head as well as sides and jaws closely scaled; broad bands of teeth be- 

 hind the incisors; villiform teeth on vomer, palatines and tongue; dorsal 

 spines low; incisor teeth lanceolate, 

 e^. Incisor teeth strong, with horizontal, backward projecting roots; soft dor- 

 sal and anal not much elevated. 

 f^. Incisor teeth well developed, each with a conspicuous horizontal pro- 

 cess or root; caudal fin moderate, about as long as the head, the outer 

 rays not 3 times as long as middle rays; junction of gill membranea 

 forming an angle Kyphosus, 19. 



