272 BULLETIN" 10 0^ UNITED STATES NATIONAL MUSEUM 



Acanthurus anmdatus Seale and Bean, Proc. U. S. Nat. Miis., v. 1. 33, 1907, 



p. 247 (Zamboanga). 

 Aca nthnurns anJudatusFowLKR and Be. n, Proc. U. S. Nat. Miis., vol.62, 1922, 



p. 57 (Ceiu). 

 Naseus marginalus Valenciennes, His^. Nai. Poiss., vcl. 10, 1835, p. 280. 



Tongatabou, Friendly Island-. — Gunther, Cat. Fish. B:it. Mus., vol. 3, 



1861, p. 333 (copied); Journ. Mus. Godeffroy, vcl. 4, 1875, p. 122, pi. 83 



(Pelew Isr.nds, Aneiteun^, Fiji). 

 Naso marginalus Herre, Philippine Journ. Sci., vol. 34, No. 4, Dec. 1927, 



p. 452, pi. 6, fig. 2, text fig. 1 (Calapan, Zamboanga, Jolo, Bungau, Sit- 



anki, Gato). 

 Acanthurus marginalus Seale and Bean, Pro?. U. 8. N ;t. Min., vol. 33, 1907, 



p. 247 (Zaiuhoang.i). 

 Priodon annidaris Valenciennes, Hist. Na<. P. is-., vol. 10, 1835, p. 302, pi. 



294 (on QuoY and Gaimard), — Bleeker, Nat. Tijds, Nederland. Indie, 



vol. 4, 1853, p. 93 (Amboina); vol. 8, 1855, p. 306 (Batoe Island). 

 Prionodon annularis Bleeker, Nat. Tijds. Nederland. Indie, vol. 3, 1852, p. 



(546) 558-(A!nb-:;ina). 

 Acanlhurus incipiens Jenkins, Bull. U. S. Fish Cjinm., w A. 22, 1902 (1903), 



p. 480, t g. 32. H in-'lulu. — Jordan and Seale, Bull. Bur. Fish., vol. 25, 



1905 (1906), p. 357 (Apia, Samoa). 



Depth 23/g to 2%; head Z% to 4%, width 1% to 2}/^. Snout 1% 

 to 1% in head from snout tip; eye 2% to 5, \ji to 3 in snout, 1 to 

 1% in interorbital; teeth 54 to 45 in jaws, very small and inconspic- 

 uous; maxillary 3J^ to 44^ in head; interorbital 2J^ to 3, convexly 

 elevated. Gill rakers 5 + 10, short, robust, conic tubercles. 



Skin everywhere minutely asperous, nearly smooth or finely vel- 

 vety to touch; in young more rough velvet. 



D. VII, 26, I to 28, 1, last spine 1^ to 2 in head, tenth ray 1^ to 

 2%; A. II, 27, I or 28, i, second spine 2% to Z}i, tenth ray 1)4 to 

 2M; caudal slightly emarginate in young, becoming broadly expanded 

 and convex behind with age, 1 to 13^; least depth of caudal peduncle 

 4% to b\i; pectoral l]/^ to 1%; ventral 1% to \%; caudal with 2 

 bony bucklers, anterior little larger or base longer than eye, not pres- 

 ent in our youngest example. 



Deep slaty brown generally, with gray tinge in fresher examples. 

 Side with many short, dusky or bluish transverse parallel lines. Iris 

 dusky. All along upper and lower boundaries of body and over most 

 of head many rather close-set deep brown spots, paler on lower sur- 

 faces. Dorsal and anal uniform dusky brown. Caudal largely pale 

 brown, base dusky. Paired fins brown. 



Mauritius, Ceylon, East Indies, Philippines, Micronesia, Polynesia, 

 Hawaii. The adult very strongly resembles Naso eoume, but may 

 easily be distinguished by its well-developed rostral protuber- 

 ance and the caudal fin without any filaments. Even the very young 

 usually show the little prominence midway on the front profile of the 

 snout. 



