BULLETIN OF THE UNITED STATES FISH COMMISSION. 333 



oblique, the tip of the preinaxillary not reaching vertical from orbit. 

 Margin of upper jaw formed entirely by the premaxillaries, whicli are 

 free laterally, but scarcely movable mesially. Maxillary not dis- 

 tinguishable, probably enveloped in the integument of the snout. Teeth 

 rather strong, short and blunt, in a double series in each jaw, appar- 

 ently wanting on the vomer or palatines. Lips developed laterally, 

 where they form a fold around the angle of the mouth; lower lip aduate 

 mesially, the upper reduced to an obsolete fold. Length of gape one- 

 fifth length of head. Nostrils two, distant, the anterior at the end of 

 the snout, almost labial, the posterior above front of orbit; both cir- 

 cular. Eye very STuall, somewhat less than interorbital width or than 

 length of snout. Distance from snout to past margin of orbit con- 

 tained 2§ times in length of head. Pseudobranchije well developed. 

 Gill-opening very narrow, reduced to a short, nearly horizontal slit, 

 extending forward from a point just below the lower base of the pec- 

 toral fin. Branchiostegals evident, apparently four in number. 



Vertical fins well developed; dorsal and anal both long, the mem- 

 brane of the last ray of each joining the base of the rudimentary rays 

 of the caudal. Distance from occiput to origin of dorsal fin equal to 

 the length of the head; rays of dorsal fin very slender, distant, the 

 membrane thin and transparent, the rays all articulate, the anterior 

 simple, the posterior bifid at tip. Vent slightly in advance of middle 

 of length of body, the anal fin beginning immediately behind it. Anal 

 rays bifid at tip, excepting the first two, which ajjpear simple. Tail 

 not isocercal, truncate at base of caudal, most of the rays of the caudal 

 springing from the expanded last vertebra. Caudal fin rounded, four- 

 fifths length of head, its rays much branched, more closely set than the 

 rays of the dorsal and anal ; rudimentary rays very numerous. 



Ventral fins small, close together, inserted slightly in advance of 

 lower end of base of jiectoral, each fin comj^osed of two rays, the inner 

 prolonged beyond the outer and bifid at tip, about as long as pectoral 

 fin and three-fifths length of head. Pectorals well developed, broad, 

 the rays branched at tip. 



Head and body entirely covered with small scales, which are close-set 

 but hardly imbricate, not arranged in series; mandible, snout, and gill- 

 membrane scaly; scales on belly and breast smaller than the others and 

 more thickly set; bases of caudal and pectoral fins scaled. 



Head 7f in length; depth 10|. D. 41; A. 36 to 38; C. 4-17-4; P. 12; 

 V. 2. 



Coloration in life : Body translucent light olive, immaculate below; 

 back and sides very finely marked with clusters of fine dots, the ground 

 color appearing as reticulations between the clusters, which are of ir- 

 regular size and form ; on the sides of the head these dots form bars 

 which radiate from the eye to the snout and lower side of the head. 



This species is known from three specimens, from 2J to 3 inches in 

 length, taken iu a rock-pool at Panama. 



