60 PROCEEDINGS OF THE ACADEMY OF [Feb., 



the radial furrow. Radial ribs much raised, large, occupying almost 

 the whole dorsal surface of disk, but leaving between them ten 

 narrow furrows radiating from the centre; closely covered with 

 rather large stumpy tubercles with thorny crowns, between which 

 lie thick, irregularly polygonal plates. Ventral interbrachial areas 

 strongly concave, closely covered with stumpy tubercles terminating 

 with one or a few thorny points. Genital slits rather large, more 

 or less parallel. 



Madreporic shield small, irregular in outline. Areas proximal to 

 ventral interbrachial regions closely covered with spiny, stumpy 

 tubercles. Oral angles ventrally projected, covered with conical 

 and acute tubercles, which become, near mouth, more or less indis- 

 tinguishable from dental papillae. Teeth and dental papillae similar, 

 conical, very acute. Oral papillae absent; sides of oral angles naked. 



Arms rather slender, long, uniformly tapered outwards, distinctly 

 annulated by double rows of coarse granules, which are entirely 

 covered with densely set, minute, compound hooks; interannuli 

 covered with coarse, smooth granules arranged in two irregular 

 rows. Ventro-laterally on either side of arm, in line with interannuli, 

 there is a series of large, round, smooth plates. At the arm bases, 

 the hook-covered annuli are usually broken in the dorsal median 

 line by conical granules terminating with one or a few thorny points. 

 Ventral side of arms with rather well-spaced tubercles, which are 

 conical or terminate with one or a few thorny points; these tubercles 

 become rounded and smooth distally. First and second tentacle 

 pores free of arm spines; third with one or two spines; fourth with 

 two or three; remainder with three. Arm spines of basal joints 

 more or less indistinguishable from conical or thorned tubercles, 

 but remainder peg-like, nearly as long as corresponding arm joint, 

 and bearing two or three denticles at tip. Oral tentacle pores, as 

 well as first and second arm tentacle pores, open by means of short 

 tubes, which bear a few spinules on the sides. Color in alcohol: 

 dull grayish purple. 



Two specimens, Sagami Sea. 



In Koehler's species, vecors and rigens, the brachial ventral surfaces 

 are smooth and the oral angles, as well as the spaces just proximal 

 to the ventral interbrachial areas, are provided with slender spines, 

 while in A. bellator (Koehler), as well as in the present species, the 

 brachial ventral surfaces, oral angles and the oral spaces referred to 

 are provided with coarse, stumpy granules or tubercles. The present 

 species, however, differs from A. bellator in fewer and distinctly longer 



