27 6 
PACIFIC SCIENCE, Vol. XIV, July I960 
olivaceus (D IX, 24-25; A III, 23-24; P 17; 
gill rakers 25-28). Two of the four olivaceus 
displayed a restriction in width and intensity of 
color of the posterior part of the orange shoulder 
band. None, however, showed a darkening of 
the white posterior area of the otherwise dark 
caudal fin. 
At the time it was collected, the specimen 
was regarded as an aberrant color form of 
olivaceus . Later at Ua Pou and Nuku Hiva in 
the Marquesas, all of the olivaceus which were 
seen were colored like this one Takaroa spec- 
imen. Therefore it now seems likely that A. 
olivaceus is subspecifically different in the Mar- 
quesas and that occasional individuals drift as 
larvae to the northern Tuamotus where they may 
intergrade with the common olivaceus form 
there. Because of a limited supply of formalin, 
only a single specimen was brought back from 
the Marquesas. It was speared in Anaho Bay, 
Nuku Hiva, on July 16, 1957. It is 196 mm. 
in standard length. The shoulder mark is 60 
mm. in length, and the orange part of it 17 mm. 
The caudal fin was pale yellowish with a black 
crescent mid-posteriorly. 
The Takaroa specimen was deposited in the 
USNM and the Nuku Hiva one at the SNHM. 
No nomenclatorial designation of the Mar- 
quesan subspecies is offered at this time. Addi- 
tional specimens should be procured from both 
the Marquesas and Tuamotus. 
A specimen of Acanthurus olivaceus in the 
intermediate stage between yellow juvenile and 
brown adult coloration was collected in the pass 
of Takaroa. It is 134 mm. in standard length. 
A year’s collecting of fishes in the Society 
Islands and Tuamotus, resulting in the taking of 
over 350 species of reef fishes, failed to yield 
any specimens of the yellow Zebrasoma f laves - 
cens (Bennett), although the brown Z. scopas 
(Cuvier) proved to be common (additional 
fin-ray counts of the latter continue to be pre- 
dominantly D IV, 24; A III, 20). When a rel- 
atively large individual of the species Acanthu- 
rus pyroferus still in the yellow color phase was 
first sighted underwater in Tahiti by the author, 
it was mistaken for Z. flavescens. The error was 
not perceived until the specimen was speared 
and regarded closely. Z. flavescens is recorded 
to date from the Hawaiian Islands, Johnston Is- 
land, Wake Island, northern Marshall Islands, 
and Mariana Islands. Eibl-Eibesfeldt (1955: 
217), in a paper concerning fish behavior, men- 
tioned yellow Z. flavescens from Cocos Island 
off Costa Rica. This record was based on under- 
water observation and should be substantiated 
with the collection of specimens. 
A specimen of Zebrasoma scopas , 25 mm. in 
standard length, which was transforming from 
the late postlarval or acronurus stage to the 
juvenile form, was collected in Papetoai Bay, 
Moorea, at a depth of 30 ft. on September 18, 
1956. It was dark brown, shading to purplish 
brown anteriorly, with vertical pale lines; the 
chest was silvery and mottled with brown; the 
ends of the median fins were narrowly hyaline. 
Another, 26 mm. in standard length, was taken 
in the bay March 21, 1957. 
Zebrasoma rostratum (Gunther) has been 
recorded previously only from the Society Is- 
lands and the Tuamotus. This distinctive long- 
snouted surgeonfish was collected by the author 
at Takaroa and Takapoto in the Tuamotus, 
where it is common on the outer reef. In spite 
of extensive collecting in the Society Islands, 
the type locality, it was not taken, nor was it 
observed. The range of the species is here ex- 
tended to include the Marquesas (one speci- 
men taken at Anaho Bay, Nuku Hiva), Caroline 
Atoll (one specimen taken off the lee reef), 
and Palmyra, Line Islands (two specimens col- 
lected by R. R. Rofen). 
A large adult Naso rigoletto Smith (1951: 
1126-1132, fig. 1), the most characteristic fea- 
ture of which is a marked depression in the 
contour of the back at the base of the spinous 
portion of the dorsal fin followed by a hump, 
was sighted by the author in the lagoon of 
Moorea, Society Islands, at a depth of 90 ft., 
but the fish was not taken. Subsequently two 
large specimens were purchased from the mar- 
ket in Papeete, Tahiti. One was shipped to the 
SNHM, and the other (Fig. 7) to the USNM. 
This is the first record of the species from the 
Pacific. It was previously known only from East 
Africa. The National Museum specimen is a 
565 mm. female lacking a horn on the fore- 
