462 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



Pectoral fins moderate, reachiug to near end of base of first dorsal, 

 1§ in head; ventrals inserted just behind axil, reaching half way to 

 vent, and about half length of head. Interspace between dorsals about 

 equal to diameter of eye. Soft dorsal and anal short and high, very 

 similar, coterminous 5 last ray of anal a little more than half length of 

 head. Caudal peduncle long, a little shorter than head. Caudal fin 

 rounded, IJ in head. 



Head 3^ in length to base of caudal ; greatest depth about 6. 



D. VI — I, 8; A. I, 8; Lat. 1. 60; 24 scales in an oblique series from 

 front of soft dorsal downward and backward to anal ; about 20 in a ver- 

 tical series. 



Color, dark, dull, olivaceous brown, paler below; jounger specimens 

 mottled below with bluish and speckled with dark brow n. Sides with- 

 out longitudinal stripes. Fins dusky, all of them finely mottled and 

 speckled with darker; the dark markings on dorsal and anal forming 

 undulated longitudinal stripes ; on pectorals and ventrals forming dark 

 bars. 



This species is known to us from three specimens, the longest about 

 a foot in length. They were obtained from near Mazatlan; according 

 to fishermen from fresh-water at Presidio. 



Culius wquidens apparently differs from other species of the group in 

 the large mouth with small equal teeth, and in the small smoothish 

 scales. 



Culius belizanus, lately described by M. Sauvage* from Belize, is very 

 similar, but has the teeth of the outer row enlarged. 



5. Centropomus robalito, sp. nov. (28102, 28132, 28150, 28310, 28321, 29562, 29564.) 

 Allied to Centropomus armatus Gill; belonging to the division of the 

 genus with large scales, and very large anal spine. 



Body comparatively elongate, the back little elevated; profile from 

 snout to base of dorsal more nearly straight than in most of the species; 

 upper outline of head somewhat concave; nuchal region little gibbous. 

 Mouth smaller than in C. armatus , the maxillary barely reachiug the 

 vertical line from the front of pupil (in C. armatus of the same size 

 reaching past front of pupil), the gape contained nearly 3 times in length 

 of head; snout long, longer than in C. armatus, 3^ in head; eye moder- 

 ate, a little more than half length of snout; preorbital with strong re- 

 trorse serrse. Top of head narrower than in C. armatus and more 

 strongly ridged; the two interior ridges on the interorbital space sep- 

 arated by a space little wider than the nostril, coalescing opposite the 

 nostrils and forming a single ridge for a little distance forward to near 

 the base of the spines of the premaxillary. Preopercle with rather dis- 

 tant teeth of nearly equal size on the entire length of its vertical margin ; 

 similar teeth on the horizontal part, growing larger backward; about 

 two teeth at the angle much longer and stronger than the others. 



*BulL Sco. Philom., Paris, 1879, 16 (reprint). 



