454 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



DEJ^CRIPTIOIV OF A IVEW SPECIES OF XEIVICHTHYS (XEXICHTIII'S 



XENlTRtrS) FROM THE liTEST COAST OF CENTRAL. AJKIERICA. 



By DAVID S. JORDAN and CHARLES II. OILB£RT. 



Xenichthys xennrus, sp. nov .(4356). 



Allied to Xenichthys californiensis Steindacliner ; belonging to the 

 group or subgenus, with the soft dorsal and anal short, not longer than 

 the spinous dorsal. 



Body rather deep, compressed ; mouth very oblique ; the maxillary 

 barely reaching the vertical from the front of the pupil. Teeth in jaws 

 small, in a band in front, which becomes a single series toward the sides ; 

 similar teeth on vomer, none on palatines or tongue. 



Preorbital distinctly serrulate ; x^reopercle evenly and finely serrate 

 on the lower margin and on the angle, its upright edge entire above 

 the angle ; opercle terminating in two flat points. Eye very large, its 

 diameter 2f in head. Gill-rakers long and slender, about two-fifths the 

 diameter of the eye, their number about 9+24. 



Lateral line with a slight curve in front, not quite concurrent with 

 the back. 



Spinous dorsal very high, the spines slender and somewhat flexible, 

 the fifth and longest about two-thirds length of head ; notch between 

 spinous and soft parts deej). Anal spines rather stouter than those of 

 the dorsal, the third longest, but little shorter than the first soft ray and 

 two-thirds the longest dorsal spine. Caudal deeply forked, the lobes 

 elongate, the middle rays but one third the length of the lower. 



Pectorals two-fifths length of head. Ventrals barely reaching vent, 

 their length equal to the distance from the snout to the posterior mar- 

 gin of orbit. 



Base of caudal scaly ; rest of the fin as well as the dorsals and anal 

 naked, the scaly sheath of the dorsal and anal, leaving the last three 

 rays free. 



Head 3^ in length ; depth 2|. D. IX-I, 11 ; A. Ill, 11; Lat. 1. 51. 



Color olivaceous above ; silvery below. 



This species is known from one specimen (jSTo. 4356 U. S. Nat. Mus.) 

 sent to the United States National Museum from San Salvador, where 

 it was taken several years ago by Capt. J. M. Dow. Its small number 

 of fin rays distinguished it at once from X. xanti and X. agassizii, while 

 from X.- californiensis it difl'ers in numerous respects. 



Indiana University, November 22, 1881. 



