OPIIIOTIIRIX VIRGATA. 



IGl 



Ophiothrix virgata Lvmax. 



Ophiothrlx virgata Lv^rvx. rrocecd. Boston Soc. Nat. Hist., VIII. ji. 82. 18G1. 



Special JIarks. — I)i.-;k be.^et with ."^lender spines. Arms tweh^e times 

 as long as the diameter of the disk ; along their upper side, a clear 

 white line, bordered by a narrow blue one on each side. 



Descripiion of a Specimen. — Diameter of di.sk, G""" ; width of arm 

 without spines, 1"""- ; length of arm, 75""° . Tootli-papilla3 thirteen, in 

 horizontal rows of two or three ; lowest ones the smallest. Teeth four, 

 very thick and stout, standing close together. Mouth-Shields heart- 

 shaped, M'ith a pretty distinct point inward, broader than long ; length 

 to l)readth, .8 : 1. Side mouth-shields meeting nearly, or quite, within. 

 Under arm-plates four-sided, with cleanly rounded corners ; length to 

 breadth (twelfth plate), .G : .7. Upper arm-plates wider without than 

 within, outer side cleanly curved, lateral sides a little re-enteringly 

 curved, and sloping towards the centre of the arm ; length to breadth 

 (eighth plate), .7 : 1. Disk above and below pretty closely covered 

 with short, tapering, thorny spines, the longest 1""" in length, which 

 nearly ojjscure the scaling of the disk, Avliich may be distinguished 

 through the skin. Radial shields nearlj- naked, separated by a single 

 line of spiny scales ; length to breadth, 1.8 : 1.2. Arm-spines six, slen- 

 der, not swelled at the point, upper one commonly longest ; lengths to 

 that of under arm-plate, 1.7, 1.7, 1.4, .9, .6, .5 :.6. Tentacle-scales very 

 distinct, round. Color, in alcohol : above, pale blue on the disk, the 

 radial shields with a speck of white at their outer ends ; arms ob.scurely 

 banded with paler and darker blue ; along the middle of the arm, a 

 clear line of white, bounded by a narrow blue line on each side ; below, 

 interbrachial spaces pale blue, the rest nearly white. 



Ophiothrix spongicola must be quite near this species, but its arms 

 are much shorter, and the pattern of color different. 



LIST OF SrECIMENS. 



Catalogue 

 Number. 



Original Number 

 Number, of Spec. 



Locality. 



When 

 Collected. 



Whence obtained. 



Nature of 

 S|>ecimeD. 



,337 



Museum of Comparative Zooloyy. 

 1 I Kincsmills Islands. I I A. Garrett. 



Alcoholic. 



21 



