Jordan and Everma7in. — Fishes of North America. 2429 



simple and not articulate, but flexible; anal fin extending from the anus, 

 which is a little nearer the anterior than the posterior extremity, to the 

 caudal, formed exclusively of soft rays; no ventrals. No lateral line. No 

 prominent anal papillte. Pyloric appendages present. A remarkable 

 genus, allied to TAimpenus, or rather to riectohranchiis, distinguished by 

 having only the posterior spines rigid. North Pacific. (uTtidOe, behind; 

 Hsvvpov, spine.) 



2785. OPISTHOCENTRUS OCELLATUS (Tilesius). 



Head 6i; depth 6j: (without caudal). D. LV to LXI, usually LIX; A. 

 36 to 39; 5 to 7 of the posterior dorsal spines rigid; Eye as long as snout, 

 4 in head, and a little more than interorbital width; maxillary extending 

 to below anterior fourth of eye; some wide pores on the head; cheeks, 

 opercles, and occiput closely scaled; strips of small scales on the branchi- 

 ostegal membrane between the rays. Dorsal rays continuous and subequal 

 in depth, the longest spine 2i in head in females, 1-^ in males; pectoral \^ 

 in head, about as long as caudal. Anus twice as far from caudal as from 

 base of pectoral. • Yellowish brown, with ill-defined darker marblings; a 

 crescentic black line on the top of the head from eye to eye; a black line, 

 obliquely directed forward, below the eye, and another, in opposite direc- 

 tion, from the eye to the opercle; 2 dark-brown streaks across the nape, 

 the second crossing the origin of the dorsal fin and extending to the base of 

 the pectoral; dorsal and caudal fins grayish olive, lighter at the base, the 

 dorsal with 5 to 9 (usually 6) large black spots at regular intervals, these 

 wanting in the males; pectorals and anal colorless. Numerous specimens 

 are from Tareinsky Bay, Kamchatka; Petropaulski Harbor, and Shana 

 Bay, Iturup Island. The number of dorsal ocelli varies from 5 to 9 in our 

 specimens, 6 being the prevailing number. Of 24 specimens whose fins we 

 have enumerated, 4 have 58 dorsal spines, 10 have 59, 5 have 60, and 5 have 

 61. In addition, 1 specimen has but 55 spines. The latter is the only male 

 in the collection and is conspicuous by the absence of distinct dorsal 

 ocelli and the great height of the vertical fins, the longest dorsal spine 

 exceeding the length of the pectoral and contained 1^ times in head. In 

 females the longest spine is 21^ in head. The anal contains 36 to 39 rays 

 in all our specimens. The dorsal fin is composed exclusively of spines, the 

 anterior flexible ones passing into the strong pungent ones near the pos- 

 terior end. The stronger spines vary from 7 to 12 in number in our speci- 

 mens. Our material answers the description of the type of 0. quinque- 

 maculatus which had 57 dorsal spines and 36 anal rays. It also agrees with 

 specimens from Petropaulski, reported on by Bean & Bean (Proc. U. S. 

 Nat. Mus. 1896, 391), with dorsal spines 58 in number. Blenniophldium 

 pelropaidi, Boulenger, has but 52 dorsal spines, but it is otherwise not to 

 be distinguished from 0. occllatus. Still more aberrant are 4 specimens 

 from Gulf of Strietok, northern Japan, mentioned by Steindachner (Ichth. 

 Beitriige, ix, 25), with but 50 to 53 spines and 32 to 34 anal rays. These 

 may represent a distinct species. OphidUim occUatuin of Tilesius must be 

 this species, but the count of fin rays is incorrect and may be taken from 



