FISHES OF THE PHHilPPINE AND ADJACENT SEAS 263 



Genus NASO Lacepede 



Naso Lacepede, Hist. Nat. Poiss., vol. 3, 1802, p. 104. Type Naso fronti- 

 cornis LacepJjde = C/iae<od!on unicornis Forskal, designated by Jordan 

 and Evermann, Genera of Fishes, pt. 1, 1917, p. 61. 



Naseus (Commerson) Lacepede, Hist. Nat. Poiss., vol. 3, 1802, p. 105. 

 Type Naseus fronticornis fuscus (Commerson) Lacepede — C/iaeiodon/ron- 

 ticornis Linnaeus, designated by Jordan and Evermann, Genera of 

 Fishes, pt. 1, 1917, p. 69. 



Monoceros (not Meusch 1787) Schneider, Syst. Ichth. Bloch, 1801, p. 180. 

 Type Monoceros biaculeatus Schneider = Chaetodoii unicornis Jorskal, 

 designated by Jordan and Eveumann, Genera of Fishes, pt. 1, 1917, p. 58. 



Nasonus Rafinesque, Analyse de la nature, 1815, p. 83. Type Naso fron- 

 ticornis Lacepede, virtually (as Nasomis Rafinesque proposed to replace 

 Naso Lacepiede). 



Priodon (Cuvier) Quoy and Gaimard, Voy. Uranie, Zool., January 29-May 

 26, 1825, p. 377, Type Priodon annulatus Quoy and Gaimard, monotypic. 



Priodontichthys Bonaparte, Prosp. Sist. Gener. Ittiol. (Saggio, dist. Anim. 

 Vert.), 1831, p. 109. Type Priodon anmdatus Quoy and Gaimard, vir- 

 tually {as Priodontichthys Bonaparte proposed to replace Prwdo/i (Cuvier) 

 Quoy and Gaimard). 



Axinurus Valenciennes, Hist. Nat. Poiss., vol. 10, 1835, p. 299. Type 

 Axinurus thynnoides Valenciennes, monotypic. 



Keris Valenciennes, Hist. Nat. Poiss., vol. 10, 1835, p. 304. Type Keris 

 anginosus Valenciennes, monotypic. 



Ceris Gunther, Zool. Record, vol. 2, Pisces, 1865, p. 187. Type Keris 

 anginosus Valenciennes. 



Callicanthus Swainson, Nat. Hist. Anim., vol. 2, 1839, p. 256. Type Aspi- 

 sums elegans 'RiJPPEi.h — Chaetodon lituratus Forskal, monotypic. 



Body oblong, compressed. Caudal peduncle with 2 large, firm, 

 bony, keeled plates, absent in young. Head in adult with prominent 

 forehead, developing very long, bony horn above eyes, absent in 

 young. Teeth small, uniserial, slightly compressed incisors with 

 edges usually serrated. Dorsal spines 5 or 6. Anal spmes 2, first 

 small spine absent. Ventral incomplete, with spine and 3 rays. 



Indo-Pacific. Mostly dark in coloration and moderate or large in 

 size. Noteworthy is the frontal horn and large ornate spines on the 

 caudal peduncle. 



ANALYSIS OF THE SPECIES 



a^. Forehead with elongated conic hornlike protuberance or crestlike hump above 

 snout in adult. 

 b^. Naso. Forehead with conic rostral protuberance. 



c^ Snout long or produced below rostral protuberance; caudal and pectoral 

 fins uniform. 

 d^. Frontal horn with a.xis on level with upper half of orbit; dorsal spines 



about half of head unicornis 



d-. Frontal horn with axis passing through orbit; dorsal spines about 3^ 



of head brachycentron 



c^. Snout moderate or very short below rostral protuberance; liind caudal 

 and pectoral edges whitish. 



e^ Frontal horn passing through center of orbit; snout short _brevirostris 



e^. Frontal projecting protuberance placed below level of orbital center; 



snout moderately produced annulatus 



