STAUEOCALYPTÜS. 16^ 



The genus, as I coDsider it at present constituted, comprises 

 tlie eleven species embodied in the following- 



Differential Key to Species. 



'f.— Dermalia nearly exclusively, or at any rate predominantly, pentactins. 



a'. — Discoctasters (both t^iibdermal and subgastral) of less than 200 h- dia.; rarely up to 

 213 i>. dia. 



a^. — Thin-walled. Gastral surface with a continuous endo^onml layer covering 

 over the exclurent canalar apertures. (AVithout prostalia. Discoctasters 80- 



100 [J- dia.; with characteristically short and cylindrical tufts of terminals) 



,S'. fasciculatus F. E. Sch. (Coast of California, 690mm.). 



6'. — Tolerably thick-walled. Gastral surface without a continuous endosomal layer, 



the excurrent canalar apertures opening freely. 



a^. — "Without prostalia (?). "With peculiar pit-like subdermal cavities whence 

 arise narrow iucurrent canals. Excurrent canalar apertures wide (up to S 



mm. dia.). (Discoctasters 128-180 jj- dia.) 



.S'. rœperl (F. E. Sen). (Coast of Patagonia, 7.31m.). 



b^. — AVith botli pentactinic and diactinic prostalia. Subdermal cavity in- 

 conspicuous. All canals narrow, even extremely narrow ; not more than 

 2 mm. wide, 

 a*. — Gastral surface smooth. Among the gastralia pentactins more numerous 



than hexactins. Rays of dermalia and gastralia smooth basally. 



(Discoctasters 150-200 [i dia.) 



S. solidus F. E. Sch... (Coast of California, 48G-1254m.). 



b*. — Gastral surface hairy on account of short projecting ends of fine 

 diactins. Gastralia hexactins. Eays of dermalia and gastralia entirely 

 rough. A considerable number of stauractins among the dermalia. 



(Discoctasters 130-213 |j. dia.) S. lubuloms n. sp. (Sagami Sea). 



/,i._Pnbgastral discoctasters larger than 220 [J-, reaching up to nearly 300 [j- or over in 

 diameter ; subdermal discoctasters considerably smaller. (Tolerably thick-walled ; 

 with pentactinic and 'generally also diactinic prostalia ; canals comparatively 

 narrow). 



c'^.— Smallest discohe:j;asters not smaller than 200 \i- dia. (m fact 228-320 \j. dia.). 

 Gastral surface smooth. Prostal pentactins small; their paratangentials up to 

 2.2 mm. in lengtli. Principal parenchymal oxydiactins under 8 mm. in length 



and 41 \i. in thickness. Gastral hexactins 80-100 [x in length of raj^s 



,S'. doidlncjl (Lambe). (Pacißc coast of IST. America, 63-512 m.). 



f/-.— Smallest di^:cohexasters (subdermally situated) much smaller than 200 H- dia. 

 Gastral surface with numerous projecting diactins. Prostal pentactins moderately 

 large; their paratangentials reaching up to 4mm. or considerably more in 

 length. Principal parenchymal oxydiactins much coarser than in c" (may be 

 80-600 iJ. thick). Gastral hexactins on the whole as large or decidedly larger 

 than in c*. 



