Mr. Darwin’s collection contains another species of _Scarus_ from the
Keeling Islands, which may probably be distinct from all those hitherto
noticed, but which being in rather a bad state of preservation, I shall
content myself with describing as well as I can, without affixing any
name to it, lest in the end it prove not new. Many of the species
enumerated in the “Histoire des Poissons” having only their colours
noticed, it requires that these should have been observed more in detail
than what Mr. Darwin’s notes furnish in this instance, in order to
decide whether it be identical or not with any of those spoken of in
that work.
FORM.—A tolerably regular oval, somewhat attenuated at each extremity:
dorsal and ventral lines of equal curvature. Nape not at all
elevated, and the profile on the whole falling very regularly and
gradually from thence to the end of the snout, though there is a
slight eminence on the forehead. Depth one-fourth of the entire
length. Jaws smooth externally, but with the true teeth very
distinct upon their surface, and much more so upon their cutting
edges than in either of the last two species. One horizontally
projecting canine at each corner of the upper jaw, but none in the
lower. The terminating lobe of the opercle is slightly emarginated
behind, the membrane projecting immediately above the notch in the
form of a short salient point. Lateral line interrupted, the upper
portion nearly straight, and not inclining downwards at its
posterior extremity: the tubes very slightly ramified, and many of
them quite simple. The scales on the body are very finely granulated
and striated: there are no large ones at the base of the caudal.
Dorsal and anal low: height of the former contained four and a half
times in the depth of the body, and exactly equalling the distance
from the upper edge of the back to the lateral line. Pectorals
somewhat triangular, the uppermost ray of all a little arcuate.
Scale between the ventrals one-third the length of those fins.
Caudal slightly crescent-shaped, when the rays are closed: when
spread, all the middle rays appear even, the uppermost and lowermost
projecting very slightly beyond them.
D. 9/10; A. 3/9; C. 13, &c.; P. 14; V. 1/5.
Length 6 inches.
COLOUR.—“Body dull reddish and greenish, the colours being blended and
mottled: fins banded lengthwise with vermillion-red: head with
waving bright green lines.”—D.—No trace of bright colours remains in
its present state, and the only indication of markings is a narrow
crescent-shaped band across the middle of the caudal.