PISCES. 139 



Priodon Cuv. Teeth serrate. Tail unarmed. Branchiostegous 

 membrane with three rays. Ventral fins with one ray pungent 

 and three soft. 



Sp. Priodon annularis Cuv., Cuv. et VAL. Poiss. x. PL 294, Indian Sea at 

 Timor. 



Acanthurus FoKSK., LACEP. Teeth serrate. Tail with a move- 

 able sharp spine on each side, the apex directed forward, or armed 

 with a row of compressed, carinate laminae (Prionurus LAC.). 

 Branchiostegous membrane with five rays. Ventral fins with single 

 ray pungent and mostly with five soft. 



Sp. Acanthurus hepatus Cuv., Teuthis hepatus L. (excl. synon. in part), Cuv. et 

 VAL. Poissons, x. PL 288 ; Acanthurus triostegus Cuv., Chcetodon triostegus 

 L. (omissa synon. in part), BBOUSSONET Ichth. Tab. 4, (and less good, SEBA 

 Thesaur. in. Tab. 25, fig. 4, LACEP. Poiss. iv. PL 6, fig. 3), yellow-green 

 with five black stripes; in the Indian and Pacific Ocean; Acanthurus 

 chirurgus BL., SCHN., Chcetodon chirurgus BLOCH, Ichth. Tab. 208, from the 

 West Indies; Acanthurus Delisiani Cuv., VAL., GUEBUT Iconogr., Poiss. 

 PL 35, fig. 2 ; Indian Ocean, from the island Mauritius to Ceylon, &c. 



Prionurus microlepidotus LAC., Cuv. et VALENC. Poiss. x. PL 292; 

 Prionurus scalprum, Acanthurus scalprum LANGSD., SCHLEGEL Faun. 

 Japon., Pise. Tab. 70. 



Naseus COMMEES., Monoceros BLOCH, SCHN. Teeth conical, in 

 a single row. Scales scarcely conspicuous. Head often tumid in 

 front of eyes or produced into a horn. Tail with two spines on 

 each side, or with triangular lamellas placed upon an oval scute. 

 Branchiostegous membrane with four rays. Ventral fins with a 

 single pungent ray and with only three soft rays. 



Sp. Naseus fronticornis COMMEBS., WILLUGHB., Hist. Pisc. t Tab. O, 4; 

 GUEBIN Iconogr. Poiss. PL 35, fig. 3, (under the name of Naseus longi- 

 rostris) ; Red Sea, Indian Ocean, South Pacific ; Naseus tuber COMMEBS., 

 LAC. Poiss. in. PL 7, fig. 3, &c. 



Axinurus Cuv. Teeth thin. Tail armed on each side with a 

 compressed, sharp, horizontal lamella. Head gibbous and without 

 horn j mouth small. Branchiostegous membrane with five rays. 



Sp. Axinurus thynnoides Cuv., Cuv. et VALENC. Poiss. x. PL 298 ; New 

 Guinea. 



The length of the intestinal canal is remarkable in these fishes. In a 

 specimen of Naseus fronticornis of 10" long, the intestinal canal was 

 observed to be 4' long j Cuv. et VAL. Poiss. x. p. 268. 



