A MONOGRAPH OF THE EXISTING CRINOIDS 51 



The next three pinnules, P 2 , P 3 , and P 4 , are 6 mm. long with 15 segments most of 

 which are about as long as broad, the basal two or three rather shorter, the distal 

 rather longer. The pinnules following are of the same length but rather broader and 

 more sharply carinate, distally becoming rather longer though remaining comparatively 

 stout. The distal pinnules are 9-10 mm. long with the first segment rounded-triangular, 

 concave distally, the second squarish, and the remainder longer than broad becoming 

 about twice as long as broad distally. 



The disk is scantily plated, except along the ambulacra, but the brachial and pin- 

 nule ambulacra are well plated. Sacculi are abundant on the brachial and pinnule 

 ambulacra. 



The color in alcohol is yellowish brown, and the containing liquid is stained the 

 same color. 



Notes. The original description of Antedon aster was entirely inadequate and 

 misleading. I wrote: 



This species is nearest to Antedon quinquecostata Carpenter (=A. com/era Hartlaub), of which 

 I have 7 Japanese examples [ = Slenometra diadema] for comparison; but the cirri are shorter and 

 proportionately stouter, with 35-40 joints, the radials [i. e., IBr series] and brachials are rounded and 

 not compressed, the former with their edges armed with fine teeth, the distal brachials strongly over- 

 lapping, the distal half as well as the distal edge of each joint beset with numerous fine teeth. 



Color in life bright yellow. 



The locality was given as Albatross station 5088. 



In the specimen from Dr. Mortensen's station 25 the centrodorsal is conical, 4 mm. 

 broad at the base and 4 mm. high, with the free parts beset with fine spinelets. The 

 cirrus sockets are arranged in 10 columns, the two in each radial area separated by a 

 bare region. The cirrus sockets are not sculptured. The cirri are XXIII, 50-64, 

 32-42 mm. long. The IIBr series are 2. The 20 arms are 90 mm. long. The distal 

 intersyzygial interval is 5-8 muscular articulations. PI is 9 mm. long with 24 segments. 

 P 2 is 7.5 mm. long with 18 segments. P 3 is 6.5 mm. long with 16 segments. The 

 distal pinnules are 9.5 mm. long with 21 segments. The disk is incised, almost naked, 

 7-10 mm. in diameter. The anal funnel is 3.5 mm. long, inserted in the right side of 

 the anal intcrradius. 



In a specimen from Mortensen's station 15, as described by Gisleii, the centrodorsal 

 is a low cone 1.8 mm. high. The cirri are XXVI, 39-47, 20-30 mm. long; the longest 

 segment is half again as long as broad. The 17 arms are 65 mm. long. The IIBr 

 series are 2. The radials are 10 times as broad as long. The IBri is four times as broad 

 as long. The IBr 2 (axillary) has a moderate synarthrial backward projection and, like 

 the IBr b an insignificant median carination. All the ossicles are bordered with fine 

 spinelets, in the distal parts of the arms covering the distal half of the brachials and the 

 weak middorsal carination. The proximal portions of the arms are rounded. The 

 intersyzygial interval is 4-6 muscular articulations. PI is 3.7 mm. long with 12 

 segments. P 2 is 2.5 mm. long with 9 segments. P s is 1.5 mm. long with 7 segments. 

 The distal pinnules are 7 mm. long with 11-13 segments and are thickly beset with fine 

 spinelets. The disk is strongly incised ; the larger diameter is 6 mm. and the smaller 

 2.5 mm. There are sparse granules along the ambulacral furrows. The anal cone is 

 1.8 mm. high. 



