274 
PACIFIC SCIENCE, Vol. IX, July, 1955 
Remarks : Plesiops cephalotaenia appears to be 
most closely related to oxycephalus. It differs 
from the latter in having only three (rarely 
four) scales across the preopercle instead of 
five or six, in having a post-orbital black 
stripe crossing the preopercle and opercle, and 
in the color of the pelvics, caudal, and dorsal 
fins. The steeper rostro-dorsal profile and the 
presence of ctenoid scales at or immediately 
behind the insertion of the pelvics distinguish 
both of these forms from the remainder of the 
genus. 
Material: Holotype , Chicago Natural History 
Museum no. 44708 from Sitankai, Sulu Ar- 
chipelago, Philippine Islands. Collected by 
A. W. Herre. Paratypes: Philippine Islands: 
Maculabo (1, USNM 146467), Mantacao (1, 
USNM 146462), Masbate (7, USNM 146466), 
Rapu Rapu (1, USNM 146460), San Miguel 
(1, USNM 146464), Sitankai (3, CNHM 
47293), Tara (1, USNM 151323). Borneo: 
Darvel Bay (1, USNM 146469). Burn (2, 
USNM 162704). New Guinea: Tanamara Bay 
(1, USNM 123384). 
Range : Philippine Islands from Mindoro 
Strait and San Miguel Bay (southeastern 
Luzon) to eastern Borneo and New Guinea. 
Probably occurring throughout the Indo- 
Australian Archipelago east of the Sunda 
Shelf. 
Plesiops oxycephalus Bleeker 
Figs, lc, 3 b 
Plesiops oxycephalus Bleeker, 1855, Nat. Tijd, 
Ned. Indie, 8: 320— Batu Islands; 1857= 
op. cit. 12: 234; 1865, Ned. Tijd. Dierk. 
2: 279; 1875, Akad. Wetens. Amsterdam, 
Verh. 15 (Pseudochr.) : 29; 1877, Atlas 
Ichthy. 9: pi. 389, fig. 7; Gunther, 1861, Cat. 
Fishes Brit. Mus. 3: 364; Vaillant, 1889, 
Soc. Philom., Bui .VIII, 1: 57; Boulenger, 
1895, Cat. Fishes Brit. Mus. 1: 341; Weber 
and de Beaufort, 1929, Fishes Indo-Aust. 
Arch. 5: 377; Fowler and Bean, 1930, U. S. 
Natl. Mus., Bui. no. 100, 10: 316. 
Smith (1952) suggests, after a study of the 
literature, that oxycephalus may be a synonym 
of coeruleolineatus Riippell. These two forms, 
however, are readily distinguished by colora- 
tion, counts, head shape, and scalation. 
Diagnosis: Dorsal spines XII; lateral line 
18-20 + 7-12; mid-lateral scales 22-24; scales 
in transverse series 2-3/ 1/8-9; total gill rakers 
on first arch 14-16; two lowest pectoral rays 
with one or two branches each ; lower pectoral 
rays free at tips or in distal third only; stand- 
ard length to 65 mm.; total length up to 97 
mm. (Bleeker, 1855); opercle yellowish, with- 
out ocellus; body scales usually with faint 
light spots; caudal with broad, orange, cres- 
centic band medially. 
Description: Dorsal XII, 7; pectoral 17-20; 
pelvic I, 4; anal III, 8; gill rakers 5-7 + 
8-10; standard length to 65 mm.; head 2.32- j 
2.51 (mean 2.40 =±= 0.02; N = 8); depth 
2.80-3.16 (mean 2.91 ± 0.05; N = 7). 
Body compressed, oblong; dorsal profile 
convex; rostro-dorsal profile moderately steep, 
bent at nape, making 35 degree angle with 
mid-lateral line; ventral profile convex, scarce- 
ly sloping from snout to pelvics; snout 
bluntly pointed in profile, slightly shorter 
than eye; mouth horizontal or somewhat ob- 
lique; maxilla reaching posterior level of orbit 
or just beyond; posterior nostril just before 
orbit, equidistant from orbit and anterior, 
tubulated nostril; diameter of orbit less than 
its distance from end of preopercle, about 
twice interorbital width. 
Dorsal origin above tip of opercle; pointed 
posteriorly; base of spinous part about three 
times length of soft part; spines increasing in 
size to tenth; first spine about two-thirds 
length of second which is subequal to eye; 
last spine subequal to distance between orbit 
and end of preopercle; longest soft ray equal 
to post-orbital part of head; membrane ex- 
tending beyond tips of spines, notched along 
front edge of spines to basal third of anterior 
spines; notch becoming shallower posteriorly, 
reaching to center of last spine. 
Anal origin opposite ninth dorsal spine; 
shape similar to that of dorsal; first spine 
three-fifths second; second spine five-sixths 
