344 U.S. NATIONAL MUSEUM BULLETIN 2 02 Vol. 2 



Head 3.8, depth 4.4; longest pectoral ray 4.1; snout tip to anus 

 2.1; anal fin base 2.5; all in standard length. Eye 4.4; snout 2.7; 

 postorbital length of head 1.7; greatest depth of body 1.1 ; least depth 

 3.1; longest pectoral ray 1.2; longest dorsal spine 2.3; all in length 

 of head. Fleshy interorbital space 2.2 in eye. 



Orbital tentacle as long as diameter of eye, single, with 4 cirri on 

 inner edge, 1 cirrus on outer edge basally and tapering to a point; 

 nuchal cirrus simple, single, on each side; nasal flap with about 8 

 cirri distally; snout profile with a little forward slant; entire edge of 

 upper lip crenulate, that of lower lip smooth; lateral line arched 

 over pectoral fin, descending to midlengthwise axis, then continuing 

 posteriorly and ending about opposite middle of length of anal fin 

 base; vertical line through doreal origin passes a trifle behind pelvic 

 fin base; dorsal fin with a deep notch over last dorsal spine; membrane 

 behind last soft dorsal ray attached to upper edge of caudal peduncle ; 

 anal origin under base of third or fourth from last dorsal spine; last 

 anal ray without membrane posteriorly; pectoral fins reaching about 

 to anus; anal spines of female small, the first embedded, those of 

 male distinct, without swollen tips on adults; posterior canines 

 on lower jaw distinct but small; teeth fine, numerous, movable, of 

 equal size in both jaws, vomer with a row of small blunt teeth; no 

 cephalic crest. 



Color in alcohol. — Background coloration plain light brown with 

 scarcely any trace of vertical bars; no dark spots in middle of sides; 

 a black dash a short distance behind eye, separated from eye by a 

 whitish area; dorsal fin barred with darker; caudal fin with 4 dark 

 bars as wide as or a little wider than paler interspaces; anal dusky, 

 with tips of rays white; pectoral with a slight trace of dusky bars 

 ventrally; underside of head with 3 or 4 V-shaped alternating light 

 and dark bars, the dark bars outlined by a white line, which is bordered 

 by a narrow line of dark pigment cells. 



Remarks. — E. plurifilis and E. niuafoouensis are very closely 

 related; they are distinguishable by minor differences in their color 

 pattern. We have considered the possibility that plurifilis represents 

 the younger stage of niuafoouensis, but since numerous specimens of 

 plurifilis are mature adults (females with large eggs) we conclude 

 they are not. 



Genus ISTIBLENNIUS Whitley 



Istiblennius Whitley, Australian Zool., vol. 10, p. 185, 1943 (type species, 

 Salarias mulleri Klunzinger). 



Fowler (Proc. Acad. Nat. Sci. Philadelphia, vol. 98, p. 177, fig. 41, 

 1946) described Salarias brevoorti from the Ryukyu Islands; an ex- 

 amination of the holotype, a female, shows that it is a synonym of 

 Istiblennius bilitonensis (Bleeker 1858). 



