﻿OPIIIOGLYPIIA SARSII. 43 



with very fine, flattened, close-set papilla3, which grow suddenly much 

 larger as they pass u^Dwards along edge of radial scale ; whole number 

 about forty ; longest ones on radial scales having a length of .6""°- 

 Papillte running along sides of basal upper arm-plates very small ; they 

 start at the inner side of second plate, and run to outer side of fourth 

 jjlate, there being about four papilla? to each plate ; outermost papilla? 

 largest. Arm-spines smooth, rounded, tapering, sharp ; second joint, 

 two spines, lengths to that of under arm-jilate, .4, .8:1; third joint, 

 three spines, .4, .8, 1.2 : 1 ; all the rest of the joints have exactly three 

 spines, except close to tip of arm ; fifth joint, 1.6, 1.6, 1.2 : 1 ; about two 

 thirds out on arm, 1, 1, 1 : .4 ; close to tip of arm, middle spine longest, 

 and equal to a little over half the length of the joint ; other two spines 

 about equal. Tentacle-scales at base of 

 arm flat and square, and rounded at the 

 corners ; in shape much like some of the 

 side mouth-papillse ; mouth tentacles sur- 

 rounded by a crown of scales, arranged 

 close together in an oval, usually nine on 

 the side next the mouth-shields, and five 

 on the other side ; sometimes, however, 

 seven on one side and six on the other ; 

 second joint, six scales, three without, and 

 three within the tentacle ; third joint, four 

 scales, two without and two within ; fourth 



joint and those just beyond, three scales, two within the tentacle, and 

 one lying between it and middle line of arm ; farther out, the last 

 mentioned scale and the one next to it grow smaller and smaller, and 

 finally disappear about three fifths out on the arm, while the third scale 

 mamtains its size, and is found quite to the tip of the ann, where it 

 becomes pointed and spear-like. Color, in alcohol : uniform dirty white, 

 or very faint brown ; disk above, and chewing apparatus below, a shade 

 darker ; color, when dry, chalky white. 



Variations. — A young one has the following characters : diameter 

 of disk, 3.7""- ; length of arms, 9"""-. Mouth-papillEe, three on each side, 

 and one at the inner apex of the mouth angle ; outer one broadest. 

 First under arm-plate largest of all ; plates immediately beyond it small, 

 their length bemg less than that of the line of juncture of the side arm- 

 plates below. Side arm-plates not meeting above till half way out on 

 the arm. Upper arm-plates proportionately longer than in the adult ; 

 two of them are mcluded by the notch in the disk. Arm-spines three ; 

 two upper ones nearly as long as arm-Joints ; lowest one much shorter. 

 There are eleven papilla?, in a close row, along the radial scales and 

 s-enital slits. The mouth-tentacles have two scales on the side next the 



