230 ART. 2. — H. MATSUMOTO : 



scale. The spines rapidly become fewer and shorter outwards, so 

 that in the tenth free arm joint, they are four in nnmber, the 

 uppermost two spines,- which are the longest, being about one and 

 a half times as long as the corresponding joint. In the distal parts 

 of the arms, the lowest spine is transformed into a compound 

 hook. 



Colour brownish black in alcohol, formerly preserved in 

 formalin. 



The present species differs from 0. cacaotica Lyman in the 

 more numerous disk scales, in the absence of a distinct central 

 rosette of the primary plates, in the not regularly arranged 

 marginal disk scales, in the narrower arms, in the concave outer 

 border of the ventral arm plates, and in the more numerous arm 

 spines ; from 0. mœrens Kœhler in the larger radial shields, in 

 tlie shape of the oral shields, in the narrower arms, in the wider 

 ventral arm plates, of which the inner and outer borders are 

 concave, and in the more numerous and longer arm spines ; and 

 from 0. obscurci (Ljungman) in the fewer rows of the dorsal inter- 

 radial disk scales, in the larger radial shields, in the narrower 

 arms, in the markedly narrowed basal dorsal arm plates, and in 

 the more numerous arm spines. 



Ojfhi'otJiela danw Vereill. 



Ophiothela dance : Verrill, Proc, Boston Soc. Nat. Hist., XII, 1869, p. 

 391^5; Lyman, Rep. Challenger, V, 1882, p. 230 ; Marktanner-Tueneretschee, 

 Ann. K. K. Naturh. Hofmus. Wien, II, 1887, p. 313 ; Döderlein, Semon 

 — Zool. Forschungsr., V, 1897, "p. 297, PI. XVn, figs. 25-25b ; Kœhler, Ball. 



1) This paper was not seen by me. 



