FISHES OF ARCTIC J^LASKA. 



501 



increasing in size posteriorly, and between the seventh, eighth, ninth, and tenth 

 rnnniug together, leaving a tip of black at the end of the eighth spine. The second 

 dorsal is black with a few circular white spots, each spot with its center on a fin 

 ray and its edge reaching to the middle of the membrane. These spots are inclined 

 to run together. The caudal mostly black; partially divided by narrow interspace 

 of white into two heavy vertical bands. The anal is colored similar to the second 

 dorsal ; the tips of the rays and edge of the membrane are white. The ventrals with 

 several black spots. The pectorals black with oval white spots on the membranes, 

 which join each other imperfectly across the rays to form four or five interrupted 

 vertical bars of black ; two white spots at base of rays. 



Locality. 



Port Clarence 



Chignik Bay 



Hereiuloeu Bay I Albatross ooU.) 

 Do 



Dorsal. Anal. 



X 15 



IX 15 



IX 16 



IX 15 



11 

 12 

 12 

 11 



Pectoral. 



15 

 10 

 15 

 16 



Sex. 



21. Oncocottus hexacornis (Richardson). 



D.,VIII or IX, 14 or 15; A., 14 or 15; P., 17; V.,1,3; Br., 6. Head (to end of 

 opercular spine), 3i in length; eye, 5 in head; snout, 3^; interorbital space, 6^; max- 

 illary, 2. 



Body slender, tapering gradually from the rather narrow depressed head to a 

 very slender caudal peduncle. The mouth is large and horizontal, the maxillary 

 reaching past the orbit. The lower jaw shorter than the upper, but not quite 

 included within it. The head smooth and without tubercles or warts. In place of 

 the supraocular and occipital spines there are four large bony elevations, each much 

 resembling the comb of a cock; the upper surface rough and scabrous. In the 

 young these four protuberances are much less developed. The occipital ridges are 

 scarcely elevated and inclose an oblong and slightly concave area, narrowest poste- 

 riorly and running into the concave interorbital space anteriorly. The nasal spines 

 are well developed, and in the older fish are inclined to be club-shaped and scabrous. 

 The upper angle of the supraclavicle is prolonged posteriorly into a strong spine, its 

 upper surface scabrous. Just at the base and immediately in front of it is a much 

 smaller spine or tubercle on the posterior end of the x)ost-temporal bone. There is a 

 spine, almost concealed in membrane, just above the base of the pectoral. 



The preopercle has four spines; the upper, which equals the orbit in length, 

 extends upward and backward and is in some specimens curved slightly inward. 

 The second spine is immediately at the base of the first and is one-half as long. It 

 is straight and extends outward and backward. The third is curved downward and 

 the fourth, at the lower angle of the preopercle, is directed forward and downward. 

 The opercular spine is rather strong and does not reach the end of the opercular flap. 

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



The lateral line runs rather high and is composed of elongated rectangular plates, 

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

 sions along the lateral line. The plates are not present on the posterior half of the 

 caudal peduncle. Above the lateral line is 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 



