A MONOGRAPH OF THE KXISTING CRINOIDS 111 



the central region dorsally are light yellowish brown; on the arms dark red-brown areas 

 alternate with others of light reddish brown. 



Notes. The preceding description is adapted from Hartlaub's description of the 

 type specimen. 



One of the specimens from Siboga station 231 (Amboina) has 10 arms 120 mm. 

 long. The centrodorsal is discoidal with the dorsal pole large, circular, and slightly 

 concave, 2.6 mm. in diameter. The cirrus sockets are arranged hi a single perfectly 

 regular marginal row. 



The cirri are XIV, 26-29, 17 mm. long, rather stout. Owing to the very crowded 

 condition of the cirrus sockets, which are all hi one regular row, the first segment of 

 the cirri, as viewed dorsally, is very narrow. From this segment onward the cirri 

 increase in width to the fourth, which is at least three times as broad as the first, and 

 then taper almost imperceptibly to the tip. All the cirrus segments are of approxi- 

 mately equal length, short, about twice as broad as long. The lateral margins of the 

 segments in the proximal half of the cirri are strongly bent, but those of the segments 

 in the distal half of the cirri are straight. Beginning on the second or third segment 

 there is a straight serrate transverse ridge, which is at first terminal, but becomes 

 median on about the fifth or sixth. On the antepenultimate segment this transverse 

 ridge is replaced by a single small median spine. The opposing spine is long, median, 

 erect, and very much longer than the minute spine on the preceding segment, being 

 in height equal to about half the width of the penultimate segment. The terminal 

 claw is about half again as long as the preceding segment, stout hi the basal third but 

 becoming slender in the distal two-thirds, and strongly curved basally but becoming 

 nearly straight distally. The dorsal surface of the cirri is broad and flat, and is rather 

 abruptly separated from the lateral surface. 



The radials are almost entirely concealed by the centrodorsal. The IBrj are very 

 short, three and one-half times as broad as long, and are widely separated from their 

 neighbors laterally. The IBr 2 (axillaries) are broadly pentagonal, twice as broad as 

 long. The synarthrial tubercles are moderately developed. The dorsal surface of 

 the arms is almost smooth. 



P a is absent. PI is 9 mm. long with 24 segments of which the first is twice as 

 broad as long and those following gradually increase in length, becoming about as 

 long as broad on the fourth and thereafter slightly longer than broad. P 2 is similar, 

 but slightly longer and slightly stouter. P 3 is similar, but is somewhat smaller and 

 shorter than P I( 7 mm. long with 16 segments. P 4 is 4.5 mm. long with 15 segments of 

 which the distal are elongate. The pinnules following are similar. The distal pin- 

 nules are very slender and are 12 mm. long. 



The color in alcohol is yellow-brown with purplish blotches on the arms. The 

 outer half of the cirri is purplish. 



Another specimen from Siboga station 231 has 14"arms 120 mm. long. All four 

 IIBr series are 4(3+4). The cirri are XVI, 23-24 (usually 23), 15 mm. long. The 

 dorsal pole of the centrodorsal is slightly concave, 3 mm. in diameter. PI is 8 mm. 

 long. P 2 is 9.5 mm. long with 22 segments. P 3 is 6.5 mm. long. P 4 and the pinnules 

 following are 4.5 mm. long and are very delicate. The large proximal pinnules are 

 somewhat stiffened. The distal pinnules are 9 mm. long. The color is the same as 

 in the specimen just described. 



