﻿90 



OPIIIOCOMA PICA. 



LIST OF SPECIMENS. 



Whence obtained. 



Museum of Comparative Zooloyrj. 



Sandwich Islands. 

 Sandwich Islands. 

 Sandwich Islands. 

 Sandwich Islands. 



A. Garrett. 

 A. Garrett. 

 A. Garrett. 

 A. Garrett. 



OpMoCOma pica Mull. & Trosch. 



Opldocoma pica MiJLL. & Trosch. Syst. Asteriden, p. 101. 

 Ophiocoma lineolata Mull. & Trosch. Syst. Asteriden, p. 102. 

 Ophiocoma sannio Lyman. Proceed. Boston Soc. Nat. Hist., VIII. p. 81. 



Special Marks. — Arms to disk as four to one ; they are banded with 

 yellowish. Six arm-spines in the adult, slender and elegant ; upper 

 ones longest, and as long as the combined lengths of three and a half 

 to four and a half under arm-plates. 



Descri^ition of a Specimen. — Diameter of disk, 27°"' ; width of ann 

 without spines, 4"""- ; length of arm about 90""-. Mouth-papillae six ; 

 three on each side. Tooth-papillaB irregularly placed, extending nearly 

 to the inner end of the mouth-shield, the lowest ones smallest ; about 

 twenty-one in number. Teeth five, lowest one very small, and nearly 

 surrounded by joapillaj ; upper one small, and somewhat pointed. 

 Mouth-shields oval, longer than broad ; length to breadth, 2.5 : 2. 

 Under arm-plates broader than long, regular, bounded without and 

 within by a curve, on the sides by re-entering curves ; length to 

 breadth (tenth plate), 1.4 : 2. Upper arm-plates very regular, bounded 

 without by a clean curve, nearly oval, but flattened a little within ; 

 length to breadth (tenth plate), 1.4 : 2.4. Disk, above and on the sides, 

 finely and closely granulated, about 45 grains to a square mm., brachial 

 spaces below naked ; showing unusually large scales, having a diameter 

 of .5°""'. Arm-spines six, remarkably slender, tapering, and regular ; 

 lengths to that of under arm-plate, 5.2, 6, 5, 4.2, 3.8, 3.2 : 1.4. Tentacle- 

 scales two, rather large and pointed. Color, in alcohol : above, very 

 dark purplish-brown ; the disk ornamented with numerous fine radiat- 

 ing lines of yellowish ; two yellowish specks at the base of each arm ; 

 about every other upper arm-plate is cross-barred with yellowish, the 

 base of the upper spine having the same color ; below, interbrachial 



