BULLETIN OF THE UNITED STATES FISH COMMISSION. 325 



aa. Scales above lateral line ia horizontal rows parallel with the lateral line ; body 

 elliptical; month small, little oblique ; sides with alternate stripes of dark 

 brown and light grayish Maculicauda.* 



13. Xenichthys xeuops, sp. nov. (29173 (eighteen specimens), 29513.) 

 Allied to A', xanil. 



Form elliptical, the body comparatively deep, compressed, the back 

 somewhat elevated ; profile nearly straight from snout to base of dorsal. 

 Head subconic, flattish above, not strongly compressed; the temporal 

 region prominent. Post-temporal, interorbital, and suborbital regions 

 somewhat cavernous, yielding to the touch. Nuchal region slightly 

 carinate. 



Mouth terminal, very oblique, the lower jaw strongly projecting, its 

 tip entering the upper profile of head. Preorbital rather narrow, its 

 least width less than half the diameter of the pupil. Teeth small and 

 feeble, in narrow bands in both jaws ; a few on vomer, none on pala- 

 tines or tongue. Nostrils similar, near together, oblong, more than 

 twice as long as broad (nearly round in X. calif orniensis.) Preorbital 

 region, upper jaw, and tip of lower jaw naked; rest of head scaly. 

 Edge of preorbital entire. Eye extremely large, half longer than snout, 

 which is somewhat longer than the width of the flat interorbital space; 

 diameter of eye 3 in length of head. Preopercle produced and mem- 

 branaceous at its angle, its vertical limb with weak, sharp teeth. Gill- 

 rakers moderate, about half diameter of pupil. 



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 xerj low; 

 eleventh and twelfth a little higher; soft dorsal long and low, its highest' 

 rays less than diameter of orbit; its base three-fourths length of head; 

 slightly longer than base of soft dorsal, equal to base of anal. Anal 

 spines small, graduated, the third two-thirds height of the soft rays. 

 Caudal moderately and equally forked, the middle rays two-thirds 

 length of outer ; length of the tin more than length of snout and eye. 

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

 and eye, or 1^ in head. Yentrals not nearly reaching vent, 1| in head, 

 their accessory scale well developed. Vertical fins with well-developed 

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

 trals mostly covered with scales; caudal ijartly scaled. 



Head 3 in length; depth 3. D. XI, 1, 18; A. Ill, 17; scales 10-51-14. 



Coloration in life: Back bluish gray, below silvery; upper part of 

 sides with seven or eight longitudinal, 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 



* Orthostocchus maculicauda Gill, Proc. Ac. Nat. Sci. Phila. 1882, 255 : HmnuJon mazat- 

 ■lanum Stcind. Ichth. Notizen VIII, 12, taf. vi, 1869. Cape San Lucas (Gill) ; Mazat- 

 \aii{Steind.); Aca^nlco {Steind.) ; Panama (frt76.). 



