NEW JAPANESE Ef'HINOlDS. 



61 



Död. The tost (74 mm. by 8(5 mm.) is widest not only on the side opposite the 

 anterior extremity of the rosette, but also in the line drawn through its 

 posterior extremity. Actinal surface concave, not {fattened as in P. 

 excelsior, Död. Suture between interambulacral and ambulacra] plates distinct- 

 ly recognizable from external surface, while that of P. japonicus, Död. is entirely 

 invisible from outside. General ground color grey, poriferous zona reddish. 

 Ambulacra! furrow reaches the ambitus, but very indistinct in P. clypeus, Dud. 

 ►Spine with red stripes, thus (littering from P. japoniius, Död. Tubercles fewer 

 than in the last mentioned species. P. subdepressus, Gray differs from the pre- 

 sent species in having the greatest width at the posterior part, in the test rising 

 suddenly at the extremities of ambulacral petals, in the lanceolate form of the 

 petals, and the yellowish-green ground color with deep carmin colored poriferous 

 zones ;1. hwnilis, Leske differs in having the uniform breadth of periostome; 

 P. rotvndin, A. Ag. differs in having a rather circulai 1 outline, spindle shaped 

 ambulacral rosette and the greatest width near centre. It is needless t<> give 

 the distinction between this and the remaining species. 

 Loc. : Bonin Islands. 



10. Echinarachnis tenuis, nov. sp. 

 Ground color white to light violet. Outline pentagonal, with a strongly 

 wavy contour. Anus lying on the abaetinal side ; the part of the test where it 

 lies not pointed. Test extremely thin. Ambulacral rosette extending half the 

 radius and widely open. Ambulacral furrow almo-t unrecognizable. Suture 

 between each two plates visible from surface. Primary and secondary spines 

 have the greatest thickness of membrane. Diameter of the largest specimen 30 

 nun. 



Loc. : Kominato (Awa). 



Printed June ÌOth, 1898. 



