364 
PACIFIC SCIENCE, Vol. IX, July, 1955 
Teuthys Swainson, 1839- Nat. hist. . . . fishes 
. . . Vol. 2, p. 255. 
Ctenodon Swainson, 1839- Nat. hist. . . . fishes 
. . . Vol. 2, p. 255. (Preoccupied by Ctenodon 
Wagler, 1830.) 
Acronurus Gronow, 1854. Cat. fish collected 
. . . p. 190. (Type species, Acanthurus 
argenteus Quoy and Gaimard.) 
Zabrasoma Seale, 1901. Bernice P. Bishop 
Mus., Occ. Pap. 1: 110. 
Harpurina Fowler and Bean, 1929- U. S. Natl. 
Mus., Bui. 100, vol. 8, p. 253. (Type spe- 
cies, Hepatus nubilus Fowler and Bean.) 
(Proposed as a subgenus; raised to generic 
rank by de Beaufort, 1951: 165.) 
Forskal (1775: 59) proposed Acanthurus as 
a subgeneric category of Chaetodon , and in it 
he included unicornis , sohal, nigrofuscus , and 
gahhm (the latter was considered by him as a 
variant of nigrofuscus). None of these was 
designated by him as the type species. Lace- 
pede (1801: 105) established the genus Naso 
and listed unicornis as a synonym of his Naso 
fronticornis (even though unicornis is an earlier 
name). Also (1802: 556) he removed sohal 
(erroneously as sohar) from Acanthurus and 
erected the genus Aspisurus for this one spe- 
cies. Aspisurus has properly been placed back 
in Acanthurus’, unicornis remains in Naso. 
Valenciennes (1837; pi. 71, fig. 2) figured 
Acanthurus xanthopterus Cuvier and Valen- 
ciennes as the type species of Acanthurus. 
Gill (1885: 278) listed "Teuthis hepatus Lin- 
naeus = Acanthurus chirurgus Bloch” as the 
type. Neither of these type designations is 
valid, for these species were not among those 
included by Forskal in Acanthurus. 
Jordan and Fowler (1902: 558) used the 
genus Acanthurus for species of Naso which 
have the frontal horn, under the belief that 
unicornis should be considered as the type of 
Acanthurus since it was the first species listed 
by Forskal in his subgeneric category Acan- 
thurus. I quote Jordan and Fowler: ‘'The first 
species named by Forskal, unicornis being 
taken as its type, Acanthurus becomes equi- 
valent to MonocerosA Later Jordan (1917: 33) 
selected Chaetodon sohal Forskal as the type 
species of Acanthurus , and both Jordan and 
Fowler reverted to the usual use of Naso. 
Should Jordan and Fowler’s statement on 
unicornis be construed as a valid type desig- 
nation, I would recommend application to the 
International Commission on Zoological No- 
menclature to preserve the common usage of 
Acanthurus and Naso. 
According to Opinion 21 of the Interna- 
tional Commission on Zoological Nomen- 
clature, the genera of Klein (1744) do not 
gain nomenclatorial status by reason of being 
quoted by Walbaum (1792); thus Rhombotides 
is not valid. Bleeker often used this name 
instead of Acanthurus . 
The genus Harpurina Fowler and Bean, in 
which de Beaufort (1951: 165) placed the 
single species nubilus Fowler and Bean, is 
characterized primarily by small teeth and VI 
or VII dorsal spines. Acanthurus thompsoni 
(Fowler) and A. bleekeri Gunther have the 
same type of dentition (and other similarities), 
but the usual IX dorsal spines. They serve to 
connect nubilus with more typical species of 
Acanthurus; thus I do not believe that Har- 
purina is a valid genus. 
Fowler (1944: 109) established the sub- 
genus Rhomboteuthis for the species Acan- 
thurus coeruleus Bloch and Schneider on the 
basis of its deep body, long pectoral fins, and 
small caudal spine. If only the Atlantic species 
of Acanthurus were classified, such a subgenus 
might be a useful criterion, but it breaks 
down when the Indo-Pacific forms are con- 
sidered, for some, like Acanthurus guttatus 
Bloch and Schneider and A. nubilus , have a 
body depth as great or greater and pectoral 
fins as long as A. coeruleus , and A. triostegus 
(Linnaeus) has a smaller caudal spine. None of 
these species could be grouped with coeruleus 
to form a natural subgeneric category apart 
from other species of Acanthurus. Better sub- 
genera could be formed by grouping A. 
achilles Shaw, A. glaucopareius Cuvier, and A. 
