CLARK: BRITTLE-STARS. 281 



were dredged in shallow water near Loggerhead Key, Tortugas. 

 Unfortunately these specimens are, like all of those in the M. C. Z., 

 diskless, but there is no doubt of their identity. 



Ophionephthys phalerata. 



Lyman, 1874. Bull. M. C. Z., 3, p. 229, pi. 6, fig. 7-9. 



This species is much nearer to 0. limicola than is any other member 

 of the genus. The resemblance is particularly noticeable aborally 

 for the upper arm-plates are distinctly wider than long in both species 

 and are not unlike in shape and size. Orally the differences are more 

 striking but the distal oral papilla of 0. phalerata is quite small, and 

 more like those of 0. limicola than are those of other members of the 

 genus; it is, however, always single apparently. The unique was from 

 the Philippines and I find no records since its original description. 



Ophionephthys aestuarii. 



Amphiura aestuarii Matsumoto, 1915. Proc. Acad. nat. sci. Phila., 67, p. 73. 



From a careful comparison of the holotype of 0. phalerata with 

 Matsumoto's description of this species, I am strongly inclined to 

 believe they are identical, but an actual comparison of specimens is 

 desirable to determine the point. The only tangible difference noted 

 is in the width of the upper arm-plates and this is probably not 

 constant. The peculiarity of the next to the lowest arm-spine re- 

 ferred to by Matsumoto is marked in the holotype of 0. phalerata. 

 Matsumoto's specimens were from Misaki, Japan. 



Ophionephthys vadicola. 



Amphiura vadicola Matsumoto, 1915. Proe. Acad. nat. sci. Philad., 67, p. 71. 



Matsumoto considers this species near 0. phalerata but the number 

 of arm-spines is a very reliable distinction. Other differences would 

 probably be obvious on direct comparison of specimens. Matsu- 

 moto's types were from Sakurajima, Kagoshima Gulf, Japan, where 

 the species occurs in abundance. Its interesting habits were de- 

 scribed by Professors Mitsukuri and Hara, (1897. Annot. zool. Jap., 

 1, p. 68). 



