PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 415 



upper eye. Length of the upper jaw equals one-third the distance from 

 the snout to the nisertion of the auaL The lower jaw equals the distance 

 from the tip of the snout to the posterior margin of the lower eye and is 

 contained 2^ times in the length of the head. Teeth moderate, equally 

 developed on both sides, in two rows in the upper jaw, those of the outer 

 row upon the blind side of the upper jaw and the anterior portion of the 

 eyed-side considerably larger than those in the inner row. The teeth of 

 the lower jaw uniserial, almost as large as in the outer row of the upper 

 jaw. 



The eyes are large, prominent, and far apart. Their longitudinal diam- 

 eter equals the length of the snout, and is contained five times in the 

 length of the head. Their vertical diameter is about three-fourths as 

 great as their longitudinal diameter. The lower eye is far in advance of 

 the upper, the vertical from the anterior margin of the upper orbit cut- 

 ting the lower orbit at a point about two-thirds the distance from its ante- 

 rior to its posterior margin. The upper eye is close to the dorsal profile, 

 separated from it by a distance equaling about one-half its longitudinal 

 diameter. The interorbital space is flattish and uneven, its width being 

 contained four times in the length of the head. A projuineut ridge 

 extends from the upper posterior margin of the lower eye to the lower 

 posterior margin of the upper eye, thence widening and curving down- 

 ward to the upper angle of the branchial aperture. The margin of 

 the pre-operculum is also somewhat elevated. The length of the oper- 

 culum is very slightly greater than the width of the interorbital space. 



There are eleven short and thick gill-rakers on the anterior arch, 

 the loi:g3st equal in length to one-third the diameter of the eye. 



The dorsal fin begins on the blind side of the body in advance of the 

 anterior margin of the lower eye; its anterior rays are almost free, the 

 longest rays behind its middle, its greatest height equal to the length 

 of the upper jaw. 



The anal is inserted under the anterior angle of the pectoral axilla. 

 Its anterior rays are less free than are those of the dorsal, about two- 

 thirds of their length being extruded from their membrane. Its outline 

 similar to that of the dorsal, but greatest height somewhat less, being 

 one-third the length of the head. 



The greatest length of the caudal equals the length of the head with- 

 out the snout, and one-fifth of the body length. Its middle rays are 

 somewhat longer than the outer rays, giving to the posterior margin 

 the outline of an obtuse angle. 



The pectoral is inserted at the tip of the opercular flap ; its second 

 and third rays much produced in a filamentous extension. Its greatest 

 length slightly exceeds li times that of the head. The pectoral on the 

 blind side has no prolonged rays ; its greatest length equalling that 

 of the upper jaw. 



The ventral on the eyed side is inserted on the ridge of the abdomen 

 slightly behind its mate, which is a little removed from the medial line. 



