176 PROCEEDINGS OF THE NATIONAL MUSEUM. 



zontal; ventral contour little convex. Depth of body about half 

 leno-th of head; width of body over pectoral bases about 1.3 in its 

 depth ; width of tail 2.25 in its depth at a point twice length of head 

 from tip of snout. 



Head 3.95 in total length ; snout 2.15 in head, its sides little con- 

 vex, straight from tip backward a distance equal to length of orbit; 

 tip of snout acuminate and spinigerous, its width, opposite anterior 

 orbital margins, 1.3 in its length ; its depth vertically above front of 

 premaxillaries 1.9; suborbital ridge strong, continuous to preoper- 

 cular angle; occipital ridges slightly converging toward their mid- 

 dle, and slightly diverging to the posterior ends; ridge above nasal 

 fossa and orbit continuous with the postorbital ridge; denticulate 

 membranous margin of preopercle produced backward as a rounded 

 lobe; margin of subopercle, at lower angle, sharply produced down- 

 ward and backward, as in all related species. Orbit oblong, the 

 vertical diameter two-thirds the horizontal diameter, which is con- 

 tained 1.8 times in the snout, nearly 4 in head; least interorbital 

 width 0.8 orbit. Mouth small, extending to below middle of pupil; 

 maxillary 4.6 in head ; teeth in bands, the outer premaxillary series 

 scarcely enlarged. Barbel short and slender, about 6 in orbit. Six 

 branchiostegals; gill membranes attached to isthmus, without a 

 free fold. 



Pyloric caeca scarcely shorter than the orbit ; 27 were counted in a 

 paratype. 



Distance from center of anus to origin of anal fin 3 in orbit, its 

 distance from base of outer ventral ray a little greater than length 

 of orbit; distance from ventral to isthmus equal to length of orbit. 

 No thoracic scaleless pit. 



Scales large, 4^ or 5 in a series from origin of second dorsal to the 

 lateral line (excluding lateral line scale) ; those on the body bear 

 usually five very strongly spinous, divergent ridges, the median ridge 

 strongest, armed with about five imbricate spines, these becoming 

 larger posteriorly on all the ridges, the last spine extending beyond 

 the margin of the scale ; some scales have 3 or 4 ridges, but none have 

 more than 5 ; the scales before the first dorsal and those on the belly 

 smaller than those on sides of body ; the scales on the median rostral 

 ridge are not strongly specialized and are elliptical in outline, bearing 

 one to four divergent crests ; the medirostral ridge is bounded on each 

 side by a definite series of scales, each of which bears- several ridges; 

 toward the tip of the snout the scales become smaller and usually 

 bear but a single keel composed of suberect spinules; the median 

 occipital scute and the scales on the occipital ridges and on the ridge 

 above the orbit bear each a single strongly spinous keel; scales on 

 ridge on upper margin of nasal fossa with about three keels ; a series 

 of large scales, similar to those of the body, extend backward from 



