﻿OPHIOCOMA PUMILA. 



a lightrbrown pattern ; under arm-spines nearly white 

 pale brown at their base, lighter at the point. 



73 



upper spines 



Vrtrialions. — A specimen with a disk 15"""- had arms 7rr"'- ; miifbrm 

 vandyke-brown above, and same below, but paler, with a lew spots and 

 bands near end of arms and on under arm-plates ; mouth-shields a little 

 broader than long, and nearly circular ; granulation of disk in inter- 

 brachial spaces below reaching nearly to genital slits on either side ; 

 two or three of side mouth-papillae soldered together, making one broad 

 one ; only three rows of tooth-papillae ; five joints each with two 

 tentacle-scales, rest with only one. A specimen with a disk of 16""- 

 had arms of 115"""-, which shows a range of length, in grown specimens, 

 of from five to seven times. Liitken gives the length as over eight 

 times the diameter of the disk. — Young, said to be this species (origi- 

 nal O.pumila Ltk.) : diameter of disk, 2.5""°-; length of arms, 12.5"""-; 

 disk covered with fine scales, over which are scattered a few grains, or 

 rather short spines. Upper arm-plates long heart-shaped, i. e. bounded 

 Avithout by a strong curve, and on sides by two straight lines, meeting 

 wdthin. Side arm-plates meeting above and below. Under arm-plates 

 longer than broad, outer side curved, latei-als re-entei-ingly curved, inner 

 laterals straight, and meeting within. One tentacle-scale. Only two 

 tooth-papillas. Mouth-shields heart-shaped, longer than broad. Arm- 

 spines four, at base of arm ; rather more slender than in adult, and a 

 little rough. Color, in alcohol : pale yellowish-brown above, arms 

 barred with whitish, and six in number. 



This species is distinguished from the more common type of Ojjhlo- 

 coma, by its long flattened arms, and less robust structure. 



LIST OF SPECIMENS. 



