A MONOGRAPH OF THE EXISTING CRINOIDS 153 



c 2 . Elements of the division series and lower brachials with large well-spaced tubercles on the 

 dorsal surface; lower pinnules not spiny; 10 arms; cirri about 28 mm. long with 29-43 



(usually about 40) segments (northwest of Sokotra; 2,194 meters) electrae (p. 156) 



ft 2 . Edges of the elements of the division series, and often the dorsal surface also, with numerous 

 fine spines. 

 c'. Cirri with more than 30 segments. 



d l . Cirri with 60-71 segments, 45-50 mm. long. 



e". Elements of the division series and lower brachials smooth dorsally, or with a few low 

 inconspicuous tubercles; synarthrial tubercles rather prominent, but no median carina- 

 tion; 10-13 arms 80-120 mm. long, and the cirri 50 mm. long with 62-71 segments 

 (Kuirachi to the Maldive Islands and southwestward to Mozambique; 797-1,398 



meters) attenuata (p. 163) 



e 2 . Elements of the division series and lower brachials with spines on the dorsal surface, 



and with a more or less narrow spinous median carination. 



/'. Elements of the division series and lower brachials with the edges all around strongly 



everted and coarsely spinous, with a coarsely spinous median carination, and with 



a few coarse spines scattered over the dorsal surface; 10 arms; cirri 30-45 mm. long, 



with 48-66 (usually 54-66) segments (Timor Sea to Luzon; 214-960 meters). 



hirsuta (p. 165) 

 p. Elements of the division series and lower brachials with the edges less strongly everted; 

 spinosity coarser, the spines more uniform in size and more thickly distributed over 

 the dorsal surface of the ossicles, also larger, so that there is less difference between 

 the spines of the dorsal surface and those of the everted edges; median carination 

 more rounded and studded with spines resembling those of the general dorsal surface; 

 10 arms about 95 mm. long, and the cirri 45 mm. long with 57+ segments (Flores 



Sea; 794 meters) margaritifera (p. 168) 



d 2 . Cirri with 40-55 segments, 30-40 mm. long. 



e> Spines confined to the edges of the elements of the division series and earlier brachials. 

 P Elements of the division series and first two brachials with the proximal and distal 

 edges prominently everted and irregularly and coarsely dentate, the dentations 

 with numerous fine spines on their tips, the lateral borders perfectly plain without 

 spines or tubercles and sharply, though narrowly, flattened against their neighbors; 

 10 arms; cirri 40 mm. long with 34-46 segments (Maldive and Nicobar Islands, 384 



meters) marginata (p. 168) 



p. Elements of the division series and lower brachials with the proximal and distal edges 

 not dentate, evenly spinous, 

 oi Elements of the division series and first two brachials bordered with thickly set 

 spines- triangular proximal brachials with projecting distal edges which increase 

 in prominence distally, in the distal third of the arms becoming long curved over- 

 lapping spines; 10-12 (usually 10) arms 110 mm. long, and the cirri 32 mm. long 

 with 50-55 segments (Hawaiian Islands; 545-641 meters), .hawaiiensia (p. 170) 

 a 2 Elements of the division series and first two brachials with the edges finely spinous; 

 distal edges of the brachials not produced; 10 arms 40 mm. long, and the cirri 30 

 mm long with 40 segments (Sagami Bay, Japan; 631 meters) ..latipinna (p. 171) 

 eh Elements of the IBr series and lower brachials with numerous thickly set very fine spines 

 on the dorsal surface; 10 arms 60-80 mm. long, and the cirri 30 mm. long with 50-oo 

 segments (Meangis Islands to southwestern Japan; S04-914 meters.. .-gracilis (p 1,3) 

 c' Cirri with 25 segments; elements of the division series and first two brachials with sharp 

 straight edges fringed with spines, and very slightly flattened sides; 10 arms 30 or 3d mm. 



long (Kermadec Islands; 1,152 meters) echmata (p. 176) 



,' Centrodorsal with the cirrus sockets never in 10 definite columns, the sockets either irregularly 



arranged with three under each radial, or in 15 columns of which the central one in each radial 



area may be reduced to a single socket _„»_,„ 



fci. Cirri with more than 40 (40-60 + ) segments; spines on the division series and arm bases coarse, 



usually more or less separated; IIBr series, when present, 2. 



843803—50 11 



a 



