DIAGNOSES OF THE SPECIES. 299 



long and thick (.some over 2-3 mm. long and over oOO u. thick). 

 Dermalia, rough pentactins; rarely stauractins. Gastralia, similar 

 liexactins with i-avs 140-1 7'3 nnn. long or even longer. Oxv- 

 hexaster, 11'')-1C)() ;/. dia.; hexactinose forms (juite numerous. 

 Discoctaster, 120-10!) /' dia. ^Microdiscohexaster, 19-20 /^ dia. 



*S'. ritt((c(nit/tt(s 1j. — Similar to S. doivUngi in general char- 

 acters and in spiculation. Body, vase-like (?). Gastral surface, 

 entirely covered witli a small-meshed endosomal lattice in which 

 the gastralia do not form a continuous lacework, but which 

 extends over all the excurrent canalar apertures. This surface 

 is beset with rather coarse projecting needles which render it 

 conspicuously spiny. Diactinic prostalia not found on the lateral 

 surface. Pentactinic prostalia with smooth or granular para- 

 tangentials reaching up to 4 mm. or more in length. Principal 

 parenchymalia may be 250 /^ thick. Dermalia, rough peutactins ; 

 rarely stanractins and diactins. Gastralia, similar hexactins with 

 rays 95-loO/'- or more in length. Oxyhexaster, 100-132/'- or 

 more in dia. ; hexactinose forms not found (entirely wanting ?). 

 Discoctaster, about loO !'■ up to nearly 300 /^ in dia. Microdisco- 

 hexaster, not found (wanting?; if present, 19 /< dia.). 



-S. itiict'orhcfHs Jj. — Tubular, laterally compressed. Giuals 

 very narrow. With inconspicuous veil, formed of pentactins in 

 which the paratangentials are regularly cruciate and measure not 

 more than 11 ra.m. in length. Dermalia generally stanractins, 

 exceptionally pentactins ; rays beset with rather strongly developed 

 microtubercles. Gastralia, similar hexactins. Oxyhexasters in 

 the subdermal region, 68-100/'- dia.; those in deeper parts, 106- 

 136 [X dia., with stronger ]'ays ; occasionally hemihexactinose ; 



