326 



U.S. NATIONAL MUSEUM BULLETIN 202 



Vol. 2 



Figure 117. — Ecsenius opsifrontalis Chapman and Schultz, holotype, USNM 142065, from 

 Rongelap Atoll. Drawn by Dorothea B. Schultz. 



ECSENIUS OPSIFRONTALIS Chapman and Schultz 



Figure 117 



Ecsenius opsifrontalis Chapman and Schultz, Proc. U. S. Nat. Mus., vol. 102, 

 p. 521, fig. 93, 1952 (type locality, Rongelap Atoll, Marshall Islands). 



SPECIMENS STUDIED 



Rongelap Atoll: Holotype, USNM 142065, standard length 31 mm. 

 Bikini Atoll: Paratype, USNM 142066, standard length 26.3 mm., Univ. 

 Washington, 1 lot, 2 specimens, 33 to 35.5 mm. 



Description. — See table 110 for counts. 



Head (tip of snout or front of upper lip to end of gill cover) 3.5 to 

 3.6; greatest depth 4.6 to 4.8; longest pectoral ray 4.0 to 4.2; snout 

 tip to anus 1.9; anal fin base 2.7 to 2.9; all in standard length. Eye 

 3.0 to 3.1; snout 3.1 to 3.4; postorbital length of head 1.4; greatest 

 depth of body 1.3 to 1.4; least depth of body 2.5 to 2.6; longest 

 pectoral ray 1.3; longest dorsal spine 1.8 to 1.9; all in length of head 

 from tip of upper lip (snout) to rear of gill cover. Fleshy interorbital 

 space 2.5 to 3.0 in eye. 



No orbital cirrus; no nuchal cirrus; a single, simple nasal cirrus 

 arising on upper edge of nasal opening; snout profile with a notable 

 backward slant of 30 to 45 degrees from the vertical; edges of both 

 lips smooth; lateral line running a dorsal course over pectoral fin 

 (with only a slight arch) and ending opposite anus without descending 

 to midlengthwise axis; vertical line through dorsal origin passes just 

 behind pelvic bases; a membrane attaches last dorsal ray to upper 

 edge of caudal peduncle but not to base of caudal fm; anal origin 

 opposite base of last or next to last dorsal spine; last anal ray with 

 membrane attaching it to ventral edge of caudal peduncle; pectoral 

 fins not reaching to anus; anal spines small, first embedded on female 

 but not on male, tips of first anal rays not swollen; posterior canines 

 on lower jaw present but minute and hidden; teeth in upper jaw fine, 

 very numerous, movable; teeth in lower jaw about 50 in number, 

 shghtly larger, the last 2 or 3 lateral teeth notably broader and larger 



