MO^OGlîArH OF JArANESE OPHIÜROIDEA. 177 



level of the ordinary ones between the apical and tlie next papilla, 

 an acute additional papilla, which together with the others closes 

 the oral slit. 



Arms long and very slender, flattened. Dorsal arm plates 

 triangular, with much rounded angles, inner sides slightly and 

 outer side strongly convex, wider than long, successive plates 

 shghtly in contact. Lateral arm plates low, joined on the sides, 

 but not meeting above ; below, the plates meet slightly beyond 

 the basal region of the arms. First ventral arm plate very small, 

 pentagonal, longer than wide ; those beyond hexagonal, nearly as 

 long as wide, slightly wider without than within, successive plates 

 a little in contact in the basal joints ; but more distally, they are 

 separated by the lateral plates, and are pentagonal. Three arm 

 spines, subequal, about as long as the corresponding arm joint, 

 conical and obtuse. Two tentacle scales, a larger adradial and 

 a smaller abradial forming nearly a right angle. 



Colour in alcohol light yellowish gray. 



This new species differs from A. daleus (Lyman) in the 

 narrower and perfectly joined radial shields, in the smaller adorai 

 shields, in the shape of tlie ventral arm plates and in the presence 

 of two tentacle scales ; and from A. intermedins (Kœhler) in the 

 shape of the radial and oral shields, in the shape of the oral 

 papilLT, especially of the infradental ones, and in the narrower 

 arms. The last species appears to be most nearly allied to the 

 present. 



Amphiacantha, g. nov. 



Disk covered with fine, imbricating scales, and scattered 

 spines. Eadial shields usually divergent, sometimes entirely 



