﻿OPIIIOCNIDA. 



133 



disk ; from 0. marginata, in the irrcgulai' arrangement of the disk-scales, 

 the dificrcnt oroportions of the arm-plates, &c. 



LIST OF SPECIMENS. 



OPfflOCNIDA* LvMm 



Disk small and delicate, furnished with uncovered radial shields ; its 

 coat of naked, overlapping scales, is beset with small thorns. Teeth. 

 No tooth-papillge. Six mouth-papillas to each angle of the mouth. 

 Arms slender, even, more or less flattened. Arm-spines short and 

 regular, arranged along the sides of the side arm-plates. Two genital 

 slits to each interbrachial space. 



SPECIES HEREIN DESCRIBED. 



0. Inspida. O. scabriuscula. 0. neapoUtana. 



Ophiocnida hispida Ltman. 



OpMolepis hispida LeCoxte. Proceed. Phil. Acad., V. p. 318. 1851. 

 Amphiura {Ophiolepis) hispida Ldtken. Addit. ad Hist. Oph., p. 119. 



Special Marks. — Disk gray (in alcohol) ; arms straw-color, figured 

 with black. Arms to disk as about ten to one. Under arm-plates 

 squarish, but little laroader than long. 



"Ot^is, snake ; xi/tfii), nettle. 



