KHABDOCALYFÏUS. 237 



b"^. — Discoctaster with terminals bent outwards in each tuft. Dermalia pentactins, 



occasionally hexactins. (Oxyhexaster witli spherical central node) 



R. tener F. E. Sen. (C. of California). 



6\ — Discoctaster more than 150 [J- in diameter. 



c". — Oxyliexasters normal, hemihexactinose and hexactinose. 



a^. — Discoctaster, 150-200 u. in dia. Dermalia pentactins, less frequently staur- 



actins. Gastralia, hexactins and pentactins 



B. ai^pcr F. E. ScH. (C. of California). 



b^. — Discoctaster, 240-300 \i.. in dia. Dermalia, stauractins and pentactins. 



Gastralia oxyhexactins. (Oxyhexaster with splierical central node) 



R. 7ioduIosn.'i F. E. ScH. (C. of California). 



d''. — Oxyhexasters, all liexactinose. Dicoctaster about 200 [i. in diameter. Dermalia 

 pentactins, stauractins and diactins. Gastralia hexactins with the proximal 

 ray 600-800 [i or more in length R. tenuis (F. E. Sch). (C. of California). 



It- — Dermalia nearly all stauractins. (Discoctaster, 180-240 \>- in dia. Oxyhexaster, 180-280 \>. 

 in dia.) R. victor Ij. (Sagami Seaj. 



«• — Dermalia nearly all or at least predominantly compass-needle-like diactins. 

 c^ — Sponge firmly attached at base to solid substratum. Gastralia hexactins. 

 c'-. — Discoctaster more than 130 \i. in dia.; re.'iching up to about 180 \3-. 



c*. — The radial axis of gastralia about as long as, or shorter than, tlie length 

 of the longest dermalia. The free proximal ray of gastralia about as long 

 as any other ray in the same spicule. 



a*. — Among the diactinic dermalia, stauractins and pentactins occur but 

 rarely. Oxyhexaster terminals more or less distinctly barbed at base. 



R. mollis F. E. Sch. (Sagami Sea). 



b*. — Among the dermalia, diactins are most numerous, but stauractins and 

 pentactins ai-e also abundant. Oxyhexaster terminals slightly rougli- 

 ened, not barbed. (Paratangentials of hypodermalia chagreened besides 



being spined) R. aiistralis Tops. (Antarctic). 



rf^.— The radial axis of gastralia nearly twice as long as the longest dermalia, 

 or even longer. The free proximal ray is considerably prolonged over any 

 other in the same spicule. (Among the dermalia, other forms tlian diact- 

 ins occur, but quite exceptionally. Oxyhexaster terminals smooth or ob- 

 soletely rough). 



c*. — Oxyhexaster only occasionally hexactinose. Discoctaster with princi- 

 pals 20-25 [J. in length ; terminal discs toothed on the external side 

 only or with the teeth much more strongly developed on that side than 



on the inner. Microdiscohexaster, 22-30 (J- dia 



R. unguiculcdus n. sp. (Sagami Sea). 



rf*.— Oxyhexaster, mostly hexactinose. Discoctaster with principals only 

 about S [J. iu length; terminal disc equally toothed all around. Micro- 

 discohexaster, 32-40 [J. in dia R. niirabilin F. E. Sch. (S. of Alaska). 



/^. — Discoctaster small ; 82-106 [i. in dia.; terminal tuft distinctly flaring at tlie 



outer end R. c((pilluiLi.>i Ij. (Sagami Sea). 



(/'. — Sponge with tinger-likc Ijasal processes and rooted in loose bottom by means of 

 anchor-needles, ((rastralia, compass-needle-like diactins like the dermalia. Discoct- 

 aster of two kinds, large (130-160 p. dia.) and small (00 [j. dia.) 



R. plumodir/iUUua KlKKP. (S. Africa). 



