110 THE VOYAGE OF H.M.S. CHALLENGER. 



Ophiochceta setosa, Ltk., Addit. ad Hist., part 3, p. 38, 18G0 ; Ljn., Dr. Goes, Opli. 

 Of. Kong. Akad., p. 639, 1871. 

 Fiji Islands. 



Species of Ophiochceta not herein described. 

 Ophiochceta (?) mixta, Lym. (PI. XXXIX. figs. 15-17). 



Ophiochceta (1) mixta, Lym., Bull. Mus. Comp. Zool., vol. v., pt. 9, p. 222, pi. ii. figs. 40-42, 1878. 

 West Indies ; 160 to 242 fathoms. 



Group II. — Arm spines on sides of side arm plates and at a strong angle to arm. 



OphiophoUs {Ophiolepis). 

 OphiopJiolis, Miill. & Tr., Syst. Ast., 1842. 



Disk more or less covered with grains, or little spines. Teeth. No tooth papillse. 

 Mouth papillse on the sides of the mouth frames. Arm spines short, flat, and stout. 

 Upper arm plates surrounded by a rim of supplementary pieces. The lowest spine of the 

 outer arm joints is a hook. General structure rather coarse and stout. Two genital 

 openings beginning outside the mouth shields. 



The disk covering, seen from within, consists of overlapping scales, and large, rather 

 thin, radial shields. To the outer end of the genital plate, which is remarkal^le for its 

 thick, tapering, cylindrical form, is attached a small, very short, curved scale. The 

 peristomial plate is small and linear, just covering the nerve ring. Otherwise of the 

 normal type, the arm bones are somewhat remarkable for their large wings. 



Table of Species of OphiophoUs. 



Eadial shields and most of upper disk naked : edges of disk and interbrachial j 



spaces below sparsely granulated, or set with minute spines. Arm spines V OpMopliolis japonica. 



longer and more slender than in the other species, . . . ' 



Eadial shields and primary plates naked, and separated by lines of granules or \ 



minute spines, which are continued on the intorbrachial spaces below. K OphiophoUs mirahilis. 



Arm spines thick and blunt, . . . . . . ) 



Disk wholly granulate or minutely spined except primary plates. Arm spines I ^ 7 • , 7,. 



thick and blunt, . . . . . , . . ) 



Similar to preceding, but only primary plates of brachial spaces are naked, . Ophioplwlis liennerlyi. 



Similar to preceding, but entire disk above and intorbrachial spaces below )„,.,,. 



'7' ' > Ophiopholts caryi. 



granulate, or spinous, . . . . . . . ) 



