A MONOGRAPH OF THE EXISTING CRINOIDS 423 



similar to P 2 , but about 10 mm. long. The pinnules as a whole are considerably more 

 delicate than are those of Ptilometra macronema. 



The plating of the disk and ambulacra is approximately as in P. macronema. 



Notes. In the specimen from Bock's station 45, according to Professor Gislen, 

 the ceutrodorsal is 2 mm. broad at the base and 2 mm. high with 5 radially arranged 

 warts on the dorsal pole. The cirri are arranged in 1 columns, 2 in each radial area, 

 with 2 or 3 cirri in each column. 



The cirri are XXIV, 67-75, the smaller number in those about the dorsal pole the 

 larger in those nearest the radials, 38-44 num. long. The earliest segments are short, 

 the fourth is about as long as broad, those from the fifth to about the twentieth are 

 half again as long as broad, and the succeeding are shorter again. The distal segments 

 are twice as broad as long with a strong dorsal spine that rises to a height equal to 

 between one-fourth and one-third the width of the segment from the thirtieth or 

 fortieth segment onward. The fifth-twelfth segments have each a large ventral spine 

 the length of which equals one-third the width of the segment on the distal edge which 

 is curved and projects over a part of the segment following. The terminal claw is 

 about as long as the penultimate segment. 



The basals project upward in the interradial angles. 



The radials are eight times as broad as long; they bear an abrupt mediodorsal 

 tubercle. The IBr : are 4 times as broad as long, hi apposition basally, with a medio- 

 dorsal crest. The IBr 2 (axillaries) are three times as broad as long with a similar 

 crest on the proximal two-thirds. The IIBr series are 2. They, and the two first 

 brachials, bear a crest similar to that on the IBr series. 



The 20 arms are 60 mm. long. The first 9 brachials are discoidal, those following 

 oblique. The distal brachials from about the fortieth onward have a slight dorsal spine 

 as in the species of Asterometra. 



Syzygies occur between brachials 3+4, 16+17, 23+24, 30+31, etc., on a sample 

 arm. 



P! is 4.5 mm. long with 11 segments. P 2 is 8 mm. long with 16 segments. P 3 is 

 8 mm. long with 11 segments. Pe is 9 mm. long with 12 segments of which the first is 

 twice as broad as long, the second is about as long as broad, and the third and following 

 from half again to twice as long as broad, prismatic and smooth. The distal pinnules 

 are 10 mm, long with 18 segments of which the outermost 6 are more delicate than the 

 preceding and slightly collar-shaped. 



In alcohol the arms and pinnules are white-gray, the cirri violet. 



In a specimen from Bock's station 48 the 14 arms are 50 mm. long; the IIBr series 

 are 2. The cirri are XV, 64-70, 35-44 mm. long. P! is 4.2 mm. long with 8 segments. 

 P 2 is 5.2 mm. long with 10 segments. P 3 is 5.8 mm. long with 10 segments. 



In a specimen from Bock's station 59 the cirri are XVI, 61-68, 30-35 mm. long. 

 Dorsal spines are developed from the twenty-second to twenty-sixth segment onward; 

 ventral spines occur from the fourth to the tenth (or twelfth, once) segments. The 

 radials are 6 times as broad as long. The IBr 2 (axillary) is twice as broad as long. 

 The 14 arms are all broken. P t is 3.5 mm. long with 7+ segments. The disk is 6.5 mm. 

 ha diameter and bears calcareous granules. This is a younger specimen than that first 

 described and differs from it in the lower and dorsally smooth centrodorsal. 



In another specimen from Bock's station 59 the centrodorsal is 3 mm. high, 



