2002 Bulletin 47, United States National Museum. 



237S. OXCOCOTTUS HEXACOBNIS (Itioliardson). 



D. VIII or IX, 14 or 15; A. 14 or 15; P. 17; V. I, 3; Br. 6. Head 31^ (to 

 end of opercular spme); eye 5; snout 3,^; iutcrorbital space Gi; maxillary 

 2. Body slender, tapering gradually from the rather narrow depressed 

 head t(^ a very slender caudal peduncle; mouth large and horizontal ; the 

 maxillary reaching past the orbit; lower jaw shorter than the upper but 

 not quite included within it. The spine on the head smooth and without 

 tubercles or warts. In place of the supraocular and occipital spines there 

 are 4 large bony elevations, each much resembling the comb of a cock, 

 their upper surfaces rough and scabrous. (In the young these 4 big bones 

 are very small or warty.) The occipital ridges scarcely elevated and 

 inclosing an oblong and slightly concave area narrowest posteriorly and 

 running into the concave interorbital space anteriorly; nasal spines well 

 developed and in the older hsh inclined to be club-shaped and scabrous; 

 upper angle of the superclavicle prolonged posteriorly into a strong spine, 

 its upper surface scabrous; just at the base and immediately in front of it 

 a much smaller spine or tubercle on the posterior end of the post-temporal 

 bone; a spine almost concealed in membrane just above base of j)ectoral; 

 preopercle with 4 spines, the upper equaling the orbit in length and extend- 

 ing upward and backward, in some curved slightly inward, covered with 

 membrane for about \ its length; the second spine immediately at the 

 base of the first and is ^ as long, straight, and extending outward and 

 backward; the third, found farther down, curved downward; the fourth, 

 at the lower angle of the preopercle, directed forward and downward and 

 sometimes entirely covered by membrane ; opercular spine rather strong, its 

 point raised from the membrane and not reaching end of opercular flap. 

 There is a slender sharp spine at the lower angle of the opercle, lateral 

 line running rather high and composed of elongated rectangular plates, 

 each with a concave depression at either end, thus making a row of ellip- 

 tical depressions along the lateral line; the plates not jiresent on the 

 posterior half of the caudal peduncle ; above the lateral line a row of rough 

 circular osseous plates, beginning on the nape and running to the base 

 of the caudal, gradually becoming smaller and nearer together; under 

 the second dorsal this row is double; below the lateral line and beneath 

 the second dorsal about 3 irregular rows of similar l)ut smaller plates. 



Adult female. — First dorsal lower than in male, scarcely rounded poste- 

 riorly but sloping almost gradually toward the base of the second dorsal; 

 third and fourth spines longest and equal to length of snout ; second dor- 

 sal abovit twice as high as first and varying a great deal in shape, the 

 membrane scarcely incised, the first 3 or 4 rays with rough, prickly 

 edges; anal oblong and slightly rounded, the middle rays longer than 

 snout, the membrane between the rays not incised; pectoral scarcely 

 reaching front of second dorsal, first 2 or 3 rays rough on their outer edge, 

 the membrane not incised ; caudal not rounded but truncated with rather 

 sharp corners, 10 developed rays, 8 of them branched; ventrals reaching f 

 to the vent, the inner ray no longer than the middle one. 



Adult male. — The first dorsal higher than in the female, the third and 

 fourth rays longest and ecjual in length to the distance from snout to 

 middle of eye, posterior end of fin more rounded ; second dorsal more than 



