﻿FISHES, GENUS ECSENIUS — CHAPMAN AND SCHULTZ 521 



ECSENIUS OPSIFRONTAUS, new specie! 

 FiGXJBE 93 



HoIoti/pe.—V.S.^M. No. 1420G5, Rongelap Atoll, Rongelap Island, 

 Marshall Group, collected by Brock, Herald and Kohler, July 25, 1946, 

 in lagoon at depth of 18 feet, standard length 31 mm. 



Pamtype.—\J.S.l:^M. No. 142006, Bikini Atoll, collected by Brock 

 and Schultz in lagoon at depth 20 to 25 feet, March 26, 1946, 1 specimen, 

 26.3 mm. 



Desciiption.— Dorsal rays XII,13; anal 11,15; pectoral 13; 

 pelvic 1,3. 



Certain measurements were made on the types, and these data are 

 recorded in thousandths of the standard length in table 2. 



Nasal cirrus single and simple, slender, rising on dorsal side of 

 nasal pore, about half diameter of eye in length ; forehead projecting 

 so that anterior slopes from level of eye back to margin of upper lip 

 at an angle of 30 to 45 degrees from the vertical ; a single, small canine 

 close behind other teeth on dentary, hidden by fold of membrane at 



Figure 93. — Ecsenius opsifronialis, new species. Holotype. (Drawn by Dorothea B. Schultz.) 



corner of mouth; depth 4.8 to 5.1, head 3.8 to 3.9, both in standard 

 length, dorsal spines all about same length, except that last is no 

 more than two-thirds length of next-to-last; membrane definitely 

 notched behind spinous dorsal; soft dorsal highest in middle, the 

 longest ray a little longer than longest spine; last ray bound to caudal 

 peduncle by a membrane which does not reach first small caudal rays; 

 both anal spines visible in both sexes ; females with a rounded, rather 

 large genital pad with a tiny nubbin on posterior edge ; males with a 

 slender tube, half length of first spine, between anus and first anal 

 spine; tips of first anal rays not swollen; longest anal rays shorter 

 than longest dorsal spine or ray ; caudal approximately truncate, the 

 upper and lower rays not exserted in specimens of the sizes available; 

 13 principal rays, with about 6 or 7 small rays above and below; 

 none of rays branched ; pectoral shorter than head by less than half 

 the diameter of eye ; pelvic fin longer than postorbital length of head 

 by more than half the diameter of eye, spine completely hidden, third 



