Fish Fauna of Johnston Is. — Gosline 
455 
down and back from the eye typical of the 
species. 
Thalassoma quinquevittata (Lay and 
Bennett) 
10 specs., 48-110 mm., 1951; 1 spec., 62 
mm., Brock, 1948. 
Distance from tip of snout to origin of 
dorsal less than distance from tip of snout to 
origin of pelvics; a dark band around chin in 
adults; several dark marks along dorsal base 
in young. 
SCARIDAE 
Calotomus sandvicensis (Cuvier and 
Valenciennes) 
7 specs., 90-235 mm., 1951. 
The species of Calotomus , like those of 
Scams (see below), are badly confused, and 
this must be considered a tentative identi- 
fication. 
Genus Scarus 
The present classification of the species of 
central Pacific parrot fishes is a mess. How- 
ever, the group is in the process of being 
monographed (Schultz, ms.). In view of this 
the aims of the present account are quite 
limited. They comprise an attempt to sep- 
arate what seem to be the three commonest 
species of the genus Scarus in Hawaiian waters 
(which happen to be the three species taken 
at Johnston) and to see to what extent the 
green and brown color phases of these species 
are correlated with sexual differentiation and 
maturity. 
KEY TO THE SPECIES OF ScarUS COLLECTED 
AT JOHNSTON ISLAND 
la. Lower (horizontal) limb of preopercular 
border relatively little developed (Fig. 
2 b, c), the length of its free edge (meas- 
ured to the point at which the border 
runs vertically) less than the distance 
from its most anterior point to the mid- 
ventral line; upper tooth plate never 
completely covered by the upper lip; 
pectoral rays usually 14 (not counting 
the small splint at the top); outline of 
the border of pelvic fins usually rounded; 
outer caudal rays never prolonged; canine 
teeth at the corners of the upper tooth 
plate, if present, low and knob like ... 2 
lb. Lower limb of preopercular border rela- 
tively well developed (Fig. 2a), its length 
equal to or greater than the distance from 
its most anterior point to the midventral 
line; upper tooth plate, when retracted, 
completely covered by the upper lip; 
pectoral rays 13 (14 in one out of 14 
specimens); pelvic outlines usually 
pointed between the 1st and 2nd soft 
rays; caudal truncate in specimens up to 
5 inches in total length (Fig. 3 a, b), 
lunate in larger specimens (Fig. 3c) and 
usually with the outer rays prolonged in 
fishes between 8.5 inches and the max- 
imum size attained (which is about 12 
inches); adults usually with 1 to 3 con- 
spicuous, conical, pointed canines at 
either side of the upper tooth plate. Two 
complete scale rows on cheek with some- 
times a third incomplete row below (Fig. 
2a); head of moderate size, less than the 
greatest depth of body in specimens over 
6 inches long dubius 
2a. Lower of the two scale rows on cheek,, 
if present, incomplete, consisting of 1 tt> 
3 scales; head relatively smaller, its 
length considerably less than the greatest 
body depth; attains at least 2 feet in 
length perspicillatus 
2b. Lower of the two scale rows on cheek 
about as long as the upper, consisting of 
5 to 7 scales; head relatively large and 
bullet shaped, its length about equal to 
the greatest depth of body; apparently 
does not reach a length of over 1 foot 
sordidus 
Scarus dubius (Bennett) 
13 specs., 39-162 mm., 1951 (brown form). 
As Scarus brunneus , Halstead and Bunker, 
1954, 1 spec. 
