164 AllT. 7. 1. IJIMA : HEXACTINELLIDA, IV. 



c^.- — Gastral surface hairy on account of short projecting ends of fine diactins. 

 Excurrent canalar apertures mostly freely open ; in some places covered 

 over by an irregularly coarse-meshed endosomal layer. Oxyhexasters largely 

 hexactinose S. affinis n. sp. (Sagami Sea). 



cP. — Gastral surface conspicuously hispid on account of projecting and rather 

 coarse diactins. All excurrent canalar apertures covered over l)y an 

 irregularly coarse-meshed endosomal layer. Oxyhexasters, rarely hexactinose. 

 »S'. entacanthus n. sp. (Saganii Sea) 



6. — Dermalia nearly exclusively, or at any rate predominantly, stauractins. 



c'. — With small and inconspicuous prostal pentactins. (Dermalia uniformly micro- 

 tubercled on all sides). Gatralia hexactins, forming a continuous lacework in the 

 endosome. Discoctasters 114-128 ij- dia S. microchetus Ij. (Sagami Sea). 



(iK — Without prostal pentactins, the dermal surface being smooth, (though in e"^ isolated 

 and slender prostal diactins may sometimes occur). 



c^. — Dermalia decidedly spiny on the external side but obsoletely microtubercled 

 on the inside of rays. Gastralia hexactins in which the free proximal rays 

 are over 450 |j. in length; forming a continuous gastral lacework over excurrent 



canalar apertures. Discoctasters very large, 500-660 a in diameter 



S. glaber Ij. (Sagami Sea). 



/-. — Dermalia slightly rough, (jastralia pentactins and stauractins, with rays up 

 to 100 [J. length ; not forming a continuous layer over excurrent canalar apertures. 

 Discoctasters 110-210 ;j. diameter & heteradinus Ij. (Sagami Sea) 



f.— Dermalia straight diactins. (Gastralia represented likewise by diactins. Disccctaster.-* 



140-200 (A dia. Sponge veiled and with long diactinic prostalia 



S. pleorhaphidcs Ij. (Sagami Sea). 



Ill the present Contribution I propose to treat in full nine 

 species wliicli I have studied. 



S. fasciculaim and S. solid us are two American species of 

 which my knowledge has been solely derived from the describer's 

 work (F. E. ScH., '99). I beg here to offer a few remarks with 

 regard to both. 



/S. fasciculalus is undoubtedly a well differentiated species. 

 Its peculiarly characterized discoctaster (only 80-100/^ large and 

 with 4-6 terminals, about 12/^ long, forming a cylindrical tuft 

 not broader than tiie principal of over 20,« length) should alone 

 be sufficient to distinguish the species from all the rest in 

 the genus. 



