322 XJ.S. NATIONAL MUSEUM BULLETIN 2 02 Vol. 2 



Color in alcohol. — ^Background coloration whitish to light tan, with 

 about 7 or 8 vertical bars represented by areas of slightly darker 

 pigment, mostly above midlengthwise axis of body, especially 

 posteriorly; dorsal fin dusky in areas corresponding to dusky vertical 

 bars on body but edge of dorsal fin white; anal fin dusky; pel vies and 

 the basal area nearby dusky, especially on adult males; often three 

 dusky transverse streaks occur on each lower side of head, one be- 

 hind corner of lower lip, second from preopercular edge and third 

 along rear edge of gill membranes; these dark streaks do not meet 

 along midline of under side of head, that area being unpigmented. 

 The dark areas are a small faint blotch on the young specimens and 

 are absent or only very faint in those about 13 to 15 mm. in standard 

 length. 



Ecology. — This common species was encountered on reefs exposed 

 to strong wave action and in the high tidal solution channels, where 

 surflike conditions also occur. At low tide, members of this species 

 remained in the solution channels or appeared on the exposed flat 

 parts of the reefs where water was a few inches deep. 



Genus ECSENIUS McCulloch 



Ecsenius McCulloch, Rec. Australian Mus., vol. 14, p. 121, 1923 (type species, 

 Ecsenius mandibularis McCulloch). — Norman, Ann. Mag, Nat. Hist., ser. 11, 

 vol. 10, p. 810, 1943. 



This genus was revised by Chapman and Schultz (Proc. U. S. Nat. 

 Mus., vol. 102, pp. 507-528, flgs. 90-96, 1952). The following key was 

 modified from that study. 



KEY TO THE SPECIES OF ECSENIUS 

 la. (See also 16 and Ic) Pectoral with 15 rays and no dark spot around anus. 

 2a. Color of head, body and vertical fins a rich, uniform brown, with no mark- 

 ings; dorsal rays XII, 19; anal 11,20. (Red Sea.) 



E. frontalis ^ (Cuvier and Valenciennes) 

 26. Color of head and body light tan with no markings other than a few scat- 

 tered black specks on upper part of caudal peduncle; a jet black band 

 as wide as eye diameter running along base of both spinous and soft 

 dorsal, outer part of fin hyaline; top and bottom of caudal fin jet 

 black to end of long rays, rest of fin hyaline; anal fin colorless; dorsal 



rays XII,18; anal 11,20 E. gravieri » (Pellegrin) 



16. Pectoral rays 13 to 15, usually 14; anal rays 11,18 or 19; a distinct dark spot 

 around anus; a large black spot on base of caudal fin; dark brown line 

 from lower edge of eye backward across gill cover; dorsal rays XII, 16 or 

 17. (Philippines.) E. stigmatura ^ Fowler 



» Salarias frontalis Cuvier and Valenciennes, Histoire naturelle des poissons, vol. 11, p. 328, 1836 (type 

 locality, Massuah, Red Sea). 

 Ecsenius frontalii Chapman and Schultz, Proc. U. S. Nat. Mus., vol. 102, p. 512, 1952. 



9 Salarias gravieri Pellegrin, Bull. Mus. Hist. Nat. Paris, vol. 12, p. 93, 1906 (type locality, Djibouti). 

 Ecsenius gravieri Chapman and Schultz, Proc. U. S. Nat. Mus., vol. 102, p. 513, 1952. 



' Ecsenius stigmatura, Fowler in Chapman and Schultz, Proc. U. S. Nat. Mus., vol. 102, p. 514, fig. 90, 1952 

 (type locality, Philippine Islands; holotype USNM 99379, paratypes USNM 111878 and 122444). 



This species was found by Schultz among specimens studied by H. W. Fowler, and which Fowler had 

 labeled as a new species of Salarias. It was described with his permission. 



