A NEW OPHIURAN FROM TITE WEST INDIES. 



By Hubert Lyman Clark, 



Of the Museum of Comparative Zoology, Cambridge, Massachusetts. 



Among the ophiurans sent to me from the U. S. National Museum 

 were two small specimens from the West Indies, collected by the 

 U. S. Bureau of Fisheries steamer ^Z&a^ross in 1887, which proved to 

 belong to the curious genus Ophiotholia. As 

 they represent a hitherto unknown species, 

 figures and a description are given herewith. 



OPHIOTHOLIA MITREPHORA, new species.a 



Disk (in the contracted condition) 4 mm. 

 in diameter, 7 mm. high; arms about 15 mm. 

 long, probably. Disk covered by numerous 

 minute scales, and scattered here and there 

 on the surface are a few short, cylindrical 

 spinelets. Radial shields apparently want- 

 ing. (Fig. 1.) Upper arm plates small, tri- 

 angular, widely separated. (Fig. 2.) Inter- 

 brachial spaces scaled like the disk. Gen- 

 ital slits moderate. Oral shields, adoral 

 plates and oral plates concealed by spatu- 

 late or fan-shaped papillae; of these the most 

 distal are smallest, while the largest are next 

 to them, and those near the apex of the jaw 

 are intermediate; oral papillae like those on 

 the jaw surface but somewhat more pointed. 

 Under arm plates small, somewhat pentagonal, but distinctly longer 

 than broad, widely separated. Side arm plates large, meeting 

 broadly below and above; each plate carries five arm spines, of 

 which the uppermost is the longest and nearly equals the joint; in 

 addition to ordinary arm spines, each plate beyond the ninth carries, 



a From nixp-i)4)6pog, signifying wearing a mitre, in reference to the peculiar mitre- 

 like appearance of the disk (fig. 1). 



Fig. ].— Side view of Ophio- 

 tholia mitrephora, showing 

 the mitre-shaped disk, the 

 upraised arms, and the num- 

 erous oral papill.*:. x •'>• 



Proceedings U. S. National Museum, Vol. 37— No. 1724. 



665 



