354 BULLETIN OF THE BUREAU OF FISHERIES. 



Color in spirits, uniform dark brown, shaded somewhat darker, almost black at tip of snout and 

 chin; base of caudal spine dusky; all the fins except pectoral dusky, almost black, darker than body 

 color; anterior two-thirds of pectoral dusky, posterior third yellowish white; no black spots at axil 

 of any fins; iris golden. 



Type no. 51759, U. S. National Museum, from Apia, length, 17 inches. 



1201. Hepatus flavog'uttatus (Kittlitz). 



Acanthv/rus flavoguttatus Kittlitz, Senckenberg Museum, 195, 1834, Caroline Is. 

 Acanthurus kittUtzi Cuvier & Valenciennes, Hist. Nat. Poiss., x, 222, 1835, Caroline Is. 



1202. Hepatus marginatus (Cuvier & Valenciennes). Caroline Is. 



Acanthurus marginatum Cuvier & Valenciennes, Hist. Nat. Poiss., x, 221, 1835, Luganor, one of the Carolines. 



1203. Hepatus triostegus (Linnaeus). Manifi. Samoa; Tahiti; New Guinea; Fiji; Fat6; Raro- 



tonga and Nukahiva (Seale); East Indies. 

 Acanthurus zebra De Vis, Proc. Linn. Soc. N. S. W., 1884, 447, Duke of York I. 



This species is the most abundant of the genus about Samoa, swarming everywhere on the reefs. 

 The black bar through the pectoral does not descend much below the fin, the caudal mark is a vertical 

 bar or else two spots in a vertical line, and the adults have the white of the belly bounded above by 

 an undulating dark line. 



Life colors of a specimen from Apia reef, called manifi, light olive, darker on back, silvery below, 

 bars black. This seems like sandwichensis, but lacks one cross-band and is very pale; only four bands 

 on sides. 



1204. Hepatus sandvicensis (Streets). Hawaii; Johnston I.; off shore islands of Mexico. 

 Acanthurus trwstcgus sandvicensis Streets, Bull. U. S. Nat. Mus., vii, 67, 1877, Honolulu. 



Acanthurus triostegus, Smith & Swain, Proc. TJ. S. Nat. Mus. 1882, 138, Johnston I. Steindachner, Sitz. Ak. Wiss. 

 Wien, 1900, 493, Honolulu, Laysan. 



Teuthis triostegus, Jordan & Evermann, Fishes North & Mid. Amer., n, 1690 (description not synonymy), 1898, off- 

 shore islands of Mexico. 



This is the most abundant species of the genus about Hawaii, where it replaces the closely allied 

 Hepatus triostegus. The differences, although slight, are constant. 



1205. Hepatus guttatus (Forster). Moana; Aau. Tahiti; Hawaii; Samoa; New Hebrides; Kings- 



mill I.; Palau; Guam; New Guinea. 

 Acanthurus guttatus Forster, in Bloch & Schneider, Syst. Ichth., 1801, 215. Giinther, Fische der Siidsee, 109, taf. 69, 

 fig. a, New Hebrides, Tahiti, Samoa, Kingsmill I., Palau, Sandwich I. Seale, Bishop Museum 1901, 110, 

 Guam. 



This strongly marked species is common at Samoa, whence we have 20 specimens. At Hawaii it 

 is rather rare. 



Life colors of aspecimen from Apia, called moana and-a'au, dark brownish olive, paler olive behind; 

 a whitish vertical bar above vent; spots on posterior parts white; caudal olive-yellow, blackish behind; 

 ventral bright yellow, dusky edged; pectoral dusky olive, paler above; no yellow; anal dull orange. 



LARVAL FORMS OF HEPATUS. 



Larval forms of Hepatus, constituting the supposed genus Acronurus of Giinther, abound in all 

 warm seas. In all cases, these are deep in body, with a large silvery area on the thorax, and with the 

 scales replaced by vertical strife. These forms can be identified only with great difficulty, and chiefly 

 by means of the count of fin-rays. The following have been described from the Pacific Ocean: 



Acanthurus argenteus Quoy & Gaimard, Voy. Uranie, 373, pi. 63, fig. 2, 1824, Maui. This is probably the young of 



Hepatus dussumieri, possibly of Teuthis matoides. 

 Acanthurus striatus Quoy & Gaimard, Voy. Uranie, 373, pi. 63, fig. 3, 1824, Guam. This is regarded by Giinther as 

 the young of Ctenoduxtus strigosus {striatus), an identification which is probably correct. We have, however, 

 three different species of young fish, all having the coloration ascribed to Acanthurus striatus, two of them 

 from Samoa and one from Tahiti. We can identify but one of them, the Ctenochsetus, which is, without much 

 doubt, the form originally named striatus by Quoy & Gaimard. 

 Acanthurus orbicularis Quoy & Gaimard, in Cuvier & Valenciennes, Hist. Nat. Poiss., x, 237, 1835, Guam. This can 



not be identified. 

 Acanthurus brevispinus Giinther, Cat., in, 346, 1861, from unknown locality; defies conjecture. 



