100 OPHIOPHOLIS KENNERLYI. 



Ophiopholis Kennerlyi Lyman. 



Ophiopholis Kennerbji Lyman. Proceed. Boston Soc. Nat. Hist., VII. p. 200. 



Special ^larhs. — No naked plates in the interbracliial spaces of the 

 disk, above. 



Description of a Specimen. — Diameter of disk, S"""" ; outer edge 

 of mouth-shield to outer corner of opposite mouth-slit, o.4°"°' ; width of 

 arm without spines, 2*"™- ; length of arm, 35.3™™-. Mouth-papillae thin, 

 flat, square, with corners rounded ; three on each side. Teeth short, 

 broad, square, stout. Mouth-shields very closely soldered with side 

 mouth-shields, rather small, nearly oval ; length to breadth, .7 : 1. 

 Under arm-plates nearly square, corners a little rounded, and outer 

 side bounded by a slightly re-entering curve ; length to breadth, 1 : 1. 

 Side arm-plates small, and little prominent. Upper arm-plates irregular 

 oval, sometimes broken in two, more or less encroached on by supple- 

 mentary pieces, which bound their outer and lateral sides ; length to 

 breadth, near base of arm, .8 : 1.5. The supplementary pieces form a 

 close line ; they are thick and angular, vary somewhat in size, and, 

 near base of arm, from seven to ten in number ; flirther out, fewer ; 

 and near the tip none at all. Disk, above, closely and evenly covered 

 with round grains, among which appear a few small, round primary 

 plates ; one in centre, and one or two in each brachial space ; none at 

 all in the interbracliial spaces ; diameter of central plate, .7"""". Disk, be- 

 low, closely set with short, stout, smooth spines, about .S™"' long. Arm- 

 spines very stout, short, thick, rounded ; the longest about length of arm- 

 joints ; lowest one much the shortest, blunt, conical ; second spine same 

 shape, but longer ; third and fourth longest, broad, thick, and blunt ; 

 fifth same shape, but shorter ; usually five spines ; sometimes, close to 

 disk, six ; near tip of arm, the lower spine has the form of a double 

 hook. Color, in alcohol : purplish pink, with obscure bands of a darker 

 shade on arms ; an obscure line of Avhitish running lengthwise of the 

 arms ; in the position of each radial shield, an irregular patch of white ; 

 below, interbracliial spaces mottled reddish and white ; mouth-apparatus 

 whitish ; lower arm-plates whitish, edged with pink ; other parts same 

 as upper surface, but lighter. 



Variations. — A specimen of about the same size as the preceding, 

 had usually three, instead of two, primary plates in each brachial space 

 on the upper surfice of the disk ; also, a distinct line of white, running 

 quite round the disk, near its edge. A young one, with a disk o"""' in 

 diameter, had arms 12.5'"'"' in length ; the arm-sj)ines were more slender, 



