1288 Bulletin 4.7, United States National Museum. 



near together, oblong, more than twice as long as broad (nearly round in 

 X. calif ornien sis} . Preorbital region, upper jaw, and tip of lower jaw 

 naked; rest of head scaly. Edge of preorbital entire. Eye extremely 

 large, longer than snout, which is somewhat longer than the width 

 of the flat interorbital space; diameter of head 3 in length of head. Pre- 

 opercle produced and membranaceous at its angle, its vertical limb with 

 weak, sharp teeth. Gill rakers moderate, about $ diameter of pupil, 

 64-14. Scales moderate, thin, somewhat ctenoid, those of the breast like 

 the others; scales on breast and back somewhat reduced. Dorsal spines 

 high, flexible, the third highest, as long as snout and eye, or 1^ in head, 

 5^ in length of body; tenth dorsal spine very low; eleventh and twelfth 

 a little higher; soft dorsal lorg and low, its highest rays less than diame- 

 ter of orbit, its base f length of head, slightly longer than base of soft 

 dorsal, equal to base of anal; anal spines small, graduated, the third 

 height of the soft rays; caudal moderately and equally forked, the mid- 

 dle rays length of outer ; length of the fin more than length of snout and 

 eye; pectoral short, not reaching nearly to vent, a little longer than snout 

 and eye, or 1-J- in head; ventrals not nearly reaching vent, If in head, 

 their accessory scale well developed; vertical fins with well-developed 

 sheaths of scales ; anal entirely scaly ; soft dorsal, pectorals, and ventrals 

 mostly covered with scales; caudal partly scaled. Coloration in life: 

 Back bluish-gray, below silvery ; upper part of sides with 7 or 8 longitu- 

 dinal, narrow, yellowish-brown streaks, some of which are continued very 

 faintly on the head; snout blackish above, yellowish on sides; mouth 

 light yellow within, with tip of tongue and membrane of lower jaw black- 

 ish anteriorly; eye with a dusky yellowish streak surrounding the iris; 

 spinous dorsal yellowish below, dusky toward the margin; other vertical 

 fins yellowish, with some scattered black points and with narrow black 

 margins; pectorals yellowish, the membrane with series of dark points 

 between the rays; ventrals white, with a dusky yellow blotch on the 

 outer $ of outer rays. Young with two dark longitudinal stripes and a 

 faint dusky spot at base of caudal. Here described from the types of 

 Xenichthys xenops, 10 inches long, from Panama. Pacific coast of tropical 

 America; from Cape San Lucas to Panama; common southward. (Named 

 for John Xantus de Yasey, who made a remarkably valuable collection of 

 fishes at Cape San Lucas.) 



Xenichthys xanti, GILL, Proc. Ac. Nat. Sci. Phila. 1863, 82, Cape San Lucas; young; JOR- 

 DAN &, FESLER, I. c., 461. 



Xenichthys xenops, JORDAN & GILBERT, Bull. U. S. Fish Com. 1881, 325, Panama; adult. 

 (Types, Nos. 29173 and 29513. Coll. Gilbert.) 



536. NEMIPTERUS, Swainson. 



Nemipterus, SWAINSON, Nat. Hist. Fishes, etc., n, 223, 1839 (filamentosus) . 

 Synagris, GUNTHER, Cat. Fish. Brit. Mus., I, 373, 1859 (furcosut,) ; not Synagris, Bleeker. 

 Dentex, BLEEKER, Systema Percarum Revisum, 278, 1875 (filamentosus) ; not of CUVIER, 

 whose type is Dentex dentex. 



This genus contains some 20 species, very closely allied to the European 

 genus Dentex, from which they are distinguished by the larger scales, 



