﻿178 OPHIOMYXA FLACCIDA. 



Ophiomyxa flaccida Lutken. (pi. ii. Fig. 6 ; Figs. 18, i9.) 



Ophiura flacckla ?>A.Y. Journ. Phil. Acad., V. p. 151. 1825. 

 Ophiomyxa caribma Lutken. Vidensk. Meddelelser. March, 1856. 

 Ophiomyxa flaccida Lutken. Addit. ad Hist. Oph., p. 138. 



Special 3Iarks. — Color, alive, lake-red or orange ; in alcohol, olive 

 green or bright green, sometimes mottled with lighter. Four to six 

 arm-spines. Arms four or five times as long as diameter of disk. 



Description of a Specimen. — Diameter of disk, 22™- ; from outer 

 side of mouth-shield to outer corner of opposite mouth-slit, lO"""'; width 

 of arm without spines, 4.5""°' ; length of arm, 102""- ; distance from 

 outer side of mouth-shield to inner points of teeth, to that between 

 outer corners of mouth-slits, 4.2 : 4.6. Mouth-papillae, four to each side 

 of the ano-le of the iaw ; the outer one is, 

 however, rudimentary, and has no saw-like 

 edge ; the others are of about equal size, but 

 the two inner ones have their saw-like edge 

 more coarsely divided than the second one. 

 Teeth eight, closely resembling mouth-papil- 

 la^ ; the upper ones with the cutting edge 

 more rounded and nearly smooth. Mouth- 

 shields and side mouth-shields without dis- 

 tinct outline, except in dried specimens ; the 

 former are rounded diamond-shape ; length 

 „ . . „ ■, ,„ ., . to breadth about 2:1.7. Side mouth-shields 



Ophiomyxa flaccida. (Upper side ) 



long triangular, nearly meeting within. Under 

 arm-plates, in dried specimens, are faintly indicated by an oval outline, 

 with a notch in the outer side ; length to breadth about 1 : 1.5. Upper 

 arm-plates, in dried specimens, appear as transverse, elongated, oval 

 ridges, with sharp lateral corners. Skin of the disk somewhat wrinkled. 

 Arm-spines four, short, flattened, conical, covered nearly to the tip with 

 skin ; their thorns numerous ; second joint, 

 one spine ; third joint, two spines ; fifth joint, 

 three spines ; ninth joint, four spines ; lengths 

 to that of the joint (twelfth joint), 1.3, 1.1, 

 Ophiomyxa flaccda u jj . 2, The uudcr ariTi-spine, near the 



Chewing Apparatus from below. _ ^ *■ -^ 



tip of the arm, has four or five little hooks 

 along its edge. Genital slits short, reaching only one half or two thirds 

 the distance to the margin of the disk, furnished with a small lobe near 

 the mouth-shields. Color, in alcohol : above, dirty olive-green, with a 

 few irregular rings of yellowish towards ends of arms ; centre of disk 



