22 AKT. 12. — S. TOKUNAGA : ON THE 



Apical system posteriorly 42 mm. wide in a test 61.5 mm. 

 long, separate from the anterior edge ; madreporite extending 

 centrally and posteriorly ; only one large genital j:>ore in the basal 

 plate adjoining the right postero-lateral interambulacrum and 

 three small indistinct pores in the plates adjoining the remaining 

 lateral ambulacra. 



Odd ambulacrum with distinct paired pores on each side ; 

 these are 30 in number in a test 61.5 mm. long : interporiferous 

 area closely covered with granules. Paired ambulacra petaloid, 

 deeply sunken, bare ; petals not increasing in width at the ex- 

 tremity as in Schizaster japonicas A. Ag., but closely converging, 

 the greatest width being in their middle portion ; anterior paired 

 flexuous, extending forwards, pores 38 in number ; posterior petals 

 forming an angle of about 75° between them, pores 22. 



Peristome eccentric towards front, 12 mm. from the anterior 

 edge, semilunar, with a projecting posterior labrum. Posterior 

 paired ambulacra of actinal side very narrow. Periproct in a 

 truncated posterior margin, which is deeply sunken. 



Peripetalous fasciole narrow, deeply re-entering at the antero- 

 paired interambulacral spaces, running almost on the edge of petal 

 in the postero-paird interambulacra, and slightly re-entering at the 

 posterior interambulacrum. Lateral fasciole narrow, meeting with 

 the former at some distance behind the extremity of the antero- 

 lateral petals. 



Tubercles close, larger on actinal side. 

 Locality : — 



Nishi-ura, in Haha-jima, Bonin Is. (Eocene) (coll. S. 

 Tokunaga). 



