﻿34 



OPHIURA APPRESSA. 



LIST OF SPECIMENS. 



Whence obtained. 



1055 

 1069 

 1188 



3Iuseum of Comparative Zoology. 

 Acapulco. I I Alex. Ag 



Panama. 



Cape St. Lucas, Cal. 



Smithsonian Institution. 



Pan 

 Panama. 



Cape St. Lucas, Cal. 

 Cape St. Lucas, Cal. 



Alex. Agassiz. 

 J. Xantus. 



Rev. T. Powell. 

 Mr. Sternberg. 

 J. Xantus. 

 J. Xantus. 



OpMura appressa Sat. 



Ophiura appressa S.A.Y. Journ. Phil. Acad., V. p. 151. 1825. 

 Ophioderma virescens Lutken. Addit. ad Hist. Oph., p. 92. 



Special Marks. — Color grayish, or variously marbled dark green and 

 yellowish ; arm-spines nine, rather short, flattened ; arms stout ; mouth- 

 shields bi-oad heart-shaped. 



Descri2ition of an Individual. — Diameter of disk, 16°"°' ; from outer 

 edge of mouth-shield to outer corner of opposite mouth-slit, 5.2'°"'- ; width 

 of arm without spines, 2.7""'; length of arm, 62°™- ; distance from outer 

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

 corners of mouth-slits, 2.7 : 2.7. Mouth-papillae, eighteen to twenty to 

 each angle of jaw, strongly flattened, longer than broad, edges rounded ; 

 second, third, and fourth (from without), and also two innermost ones, 

 broader than the others ; outermost one of all rounded, sharp, tapering. 

 Teeth five, broad, stout, somewhat pointed ; uppermost one narrow and 

 sharp ; uppermost and lowest smaller than other three. Mouth-shields 

 very broad, rounded, heart-shape, length to breadth, 1.3 : 2 ; outer side 

 usually straight, or slightly re-entering ; corners cleanly rounded. Side . 

 mouth-shields entirely covered, except a small rounded piece, connecting 

 mouth-shield with innermost arm-plate. Under arm-plates a little over- 

 lapping, longer than broad ; * in front rounded ; sides re-enteringly 

 curved, where tentacle-scales encroach ; inner laterals very short, and 

 sloping towards middle of arm ; inner side straight ; length to breadth, 

 twelfth plate, 1 : .8. First plate oval diamond-shape ; length to breadth, 

 .7 : 1. Second plate like those beyond, but rather shorter and wider ; 



* The form of the arm-plates applies to the portion that can he seen without preparation ; 

 some parts are hidden by the tentacle-scales and the neighboring plates. 



