Vol. XXIX, pp. 225-226 December 16, 1916 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



A NEW BRITTLE-STAR OF THE GENUS OPHIOMITRA 

 FROM SOUTHERN JAPAN. 



BY AUSTIN H. CLARK.* 



During the cruise of the ^'Albatross'' in Japanese waters in 

 1906 the following ophiuran, which appears to represent an 

 undescribed species, was collected. 



I take great pleasure in naming it in honor of Professor H. 

 Matsumoto, of Sendai University. 



Ophiomitra matsumotoi sp. nov. 



The disk is 8.5 mm. in diameter, rounded pentagonal to nearly circular 

 in shape. 



Excepting for the radial shields, the disk is covered with rather large 

 scales, each of which carries a large nearly spherical granule covered with 

 small needle-like points. These granules, which are well spaced, are 

 largest in the center of the disk, where there are about three in 1 mm., 

 becoming much smaller at the interbrachial borders. 



The visible portions of the radial shields resemble those of 0. granulosa 

 Lyman, but the borders are less well defined. 



The general appearance of the dorsal surface of the disk is much the 

 same as in 0. granifera Liitkin and Mortensen, except that the granules 

 are larger and are absent from the outer borders of the radial shields and 

 from the first two arm plates. 



In the interbrachial areas on the lower surface of the disk the granules 

 are confined to the central portion, and are few, coarse, and widely 

 separated. 



The oral shields are similar to those of 0. granifera, but are slightly 

 smaller. 



The side mouth shields are similar to those of 0. granifera, but narrower, 

 with more nearly parallel sides. 



The mouth papillfe are three (rarely four), stout and swollen, only those 

 of the innermost pair sharp pointed. 



• Published with the permission of the Secretary of the Smithsonian Institution. 



40— Proc. Biol. Soc. Wash., Vol. XXIX, 1916. (225) 



