NO. 24 FOUR NEW BRITTLESTARS CLARK 3 



formed into a stout, glassy tipped hook with the sharp, transparent 

 point directed outward, and a supplementary sharp tooth below it, the 

 lower arm spine remaining short, stout, and peglike. 



OPHIOMUSIUM ROSACEUM, n. sp. 



Plate 2, figs. 3, 4 



Locality. — Caroline station loi ; Virgin Islands (lat. i8°45'4o" N., 

 long. 64°48' W.) ; 300 fathoms ; March 4, 1933. One specimen 

 (U.S.N.M. no. E.5196 [type]). 



Description. — The disk is circular, nearly flat, 6 mm in diameter, 

 and the slender arms are 25 mm long. The plates on the aboral sur- 

 face are few in number and regular in arrangement. 



The center of the disk is occupied by a circular plate surrounded 

 by five rounded slightly larger plates, radially situated, between the 

 inner ends of which, and lying interradially on the central plate, are 

 five small rounded triangular plates. Beyond each of the rounded 

 radially situated plates is a triangular plate with somewhat convex 

 sides that separates the inner thirds, or somewhat more, of the inner 

 ends of the radial shields, which, except for this, are in contact. In 

 the interradial line lying over the suture between each pair of rounded 

 radially situated plates is a five-sided plate with the angles more or 

 less broadly rounded, somewhat longer than broad, of which the two 

 sides adjoining the radial shields converge to the distal edge, which 

 is of about the same length. On the distal edge of this plate rests a 

 very long plate with diverging sides that extends to the edge of the 

 disk, separating the radial shields. The distal ends of the radial 

 shields are separated from the arm base by a low triangular plate, the 

 obtuse angle of which lies on the line separating the two radial shields 

 of each pair. 



On the oral surface the mouth shields are large ; their distal edge 

 is longer than the adjoining sides, which make a right angle with it. 

 At the point where these sides turn to converge to the inner angle the 

 plate is abruptly produced laterally in the form of a broad angular 

 point supporting the inner end of the large genital plate. Resting on 

 the distal edge of the mouth shields is a large trapezoidal plate occupy- 

 ing the entire area between the genital plates, which is gradually and 

 regularly curved upward so as to form the interradial- lateral edge of 

 the disk. The jaw plates are large, triangular, and rather more than 

 twice as broad as high. They are bordered with five mouth papillae 

 of uniform height, of which the first and third, counting from the 

 base, are twice as long as the others, or even longer. The apex of the 



