450 THE FUR SEALS OF THE P-KIBILOF ISLANDS. 



64. Hesagrammos lagocephalus (Pallas). (Plates LI, LII.) 



Sexagrammus decagrammus Bean and Bean, Proc. U. S. Nat. Mus., 1896, 383 (Petropaulski) ; not 

 of Pallas. 



Numerous specimens from Eobben Island, one specimen each from Bering and 

 Iturup islands. It is not yet known from the American coasts. It is recorded by 

 Bean and Bean from Petropaulski under the erroneous name of H. decagrammus. 

 Young specimens up to 20 cm. in length have the scales all rough ctenoid, as in H, 

 asper and H. octogrammus. Specimens 30 cm. long have most of the scales smooth, a 

 few along middle of sides still ctenoid. In an adult 54 cm. long all the scales are 

 smooth, those on head and nape partially imbedded. 



In shape and general appearance this species much resembles H. octogrammus. 

 It has a deep caudal peduncle, a convexly rounded caudal fin, and a rather bluntly 

 rounded snout. 



Head, 3f to 4 in length; depth, 3f to 3f. D., XX to XXII, 22 to 24; A., 22 to 24; 

 P., 20 to 21. Outer row of teeth enlarged in both upper and lower jaws. Teeth on 

 vomer and front of palatines. Maxillary extending to below middle of eye in adults, 

 2^ in head (2| in young). A small flap above eye, fringed along the margin. No 

 tentacles on nape. Fins high, the spinous dorsal deeply notched, the last sjjine 

 somewhat longer than the one preceding. In the adult the fifth spine is the longest, 

 nearly half length of head, the third and fourth spines nearly equal to the fifth. 

 Prom the fifth the spines gradually diminish in height to near the end of the fin, 

 when they become rapidly shortened to form the notch. 



Caudal very broad at base, convex at its posterior margin even when the fin is 

 closed. Pectorals broadly rounded, rather short, the longest rays 1^ to H in head, 

 not nearly reaching vertical from vent. Ventral fins 1| to 2 in head, short and rounded 

 in the young, becoming longer and more pointed in adults. The pectoral and ventral 

 rays are very broad, especially toward their tips, and are much branched. The soft 

 rays of dorsal and anal fins are cleft on terminal fifth, as in other species, the two 

 halves not diverging. 



There are five lateral lines on each side, as usual, two dorsal, a median, and two 

 ventral. The upper dorsal line is continued to beyond middle of second dorsal fin, 

 usually ending under the fourteenth or sixteenth rays. The lower dorsal line and the 

 median line are extended to base of caudal. The upper ventral line originates below 

 and in front of the pectoral fin, passes immediately above base of ventral, to which it 

 does not send a separate branch, and terminates opposite middle of anal fin. The 

 lower ventral line is single on breast, forks in advance of middle of ventral fins, ttie 

 branches passing to base of caudal. 



In the young the scales are all ctenoid except those in mid-yentral region, breast, 

 prepectoral area, and sides of head. The snout, subocular ring, suborbital stay, 

 iuteropercle, and usually the lowermost portion of subopercle,'scaleless. Basal half 

 or more of caudal, iind basal third of soft dorsal, with the membrane densely scaled. 

 Pectoral basis also densely scaled. Scales on breast not greatly reduced; more than 

 half as large as tlioise on middle of sides. Median lateral line with 110 pores. Eight 

 or 9 scales in an oblique series between median line and the one above it. 



Color in most of our specimens a nearly uniform warm brown, lighter on under 

 parts, marked only , with irregular, small, black spots and lines, .which may extend on 

 the dorsal and pectoral fins. The anals and ventrals are blackj the thickened tijis of 



