A MONOGRAPH OF THE EXISTING CRINOIDS 141 



The specimen from Bock's station 5 was thus described by GislSn: The centro- 

 dorsal is large, flattened, slightly concave in the center, with calcareous granules 

 which toward the margin are arranged in about 10 rays. It is 5 mm. in diameter and 

 0.8 mm. high, with the bare dorsal pole 3.5 mm. in diameter. The cirri are XXVIII, 

 14-17, from 11 to 17 mm. long. The shorter dorsal cirri have 14 or 15 and the longer 

 ventral have 16 or 17 segments. The cirri are arranged in two closely crowded alter- 

 nating rows. The second segment is about as long as broad, and the third is a little 

 longer and is slightly constricted centrally, as are most of the segments following. 

 The fifth-seventh segments are twice as long as broad, and those succeeding are from 

 one-half to one-quarter again as long as broad, and are without dorsal spines. The 

 penultimate segment is one-fifth again as long as broad with a median very weak 

 opposing spine the height of which is equal to about one-fifth the width of the segment. 

 The terminal claw is slender, somewhat curved, and is longer than the penultimate 

 segment. The radials and the IBri are concealed by the centrodorsal except for the 

 distal edge of the latter. The IBri are united laterally. The IBr 2 (axillaries) are tri- 

 angular, four times as broad as long. The IIBr series are 4(3+4). The IIBri are twice 

 as long exteriorly as ulteriorly and are united ulteriorly. There is a synarthrial 

 tubercle on the articulation between the first two elements of the IIBr series, and 

 another inconspicuous one on the articulation between the first two brachials. The 

 20 arms (or perhaps 19, as one of the IIBr series is broken off at the syzygy between 

 the two outer elements) are 70 mm. long. The first-eighth brachials are discoidal. 

 The proximal brachials are short, and the outer are about as long as broad. All the 

 distal brachials are somewhat compressed in the middle, with the distal ends everted 

 and armed with small spines. There are 17 brachials in each 10 mm., or 15 if the 

 syzygial pairs are counted as units. On a typical arm syzygies occur between brachials 

 3+4, 11 + 12, 21+22, 30+31, and distally at intervals of about seven muscular 

 articulations. The pinnule on the IIBr series is 7 mm. long with 29 segments, of which 

 the first seven are stout and those following more slender. P, is 13 mm. long with 33 

 segments, which are a little longer than broad, the second-fourth with small prom- 

 inences resembling those on the proximal pinnules of, for instance, Comatula pectinata, 

 but very much less developed. P 2 is of about the same length. P 3 is about 10 mm. 

 long. P a is 5.5 mm. long, with about 20 segments. The genital pinnules are 12 mm. 

 long. The distal pinnules are 8 mm. long, with 20 segments. The basal pinnule 

 segments, especially on the proximal pinnules, have small spiny prominences. There 

 are three pairs of small sacculi to each pinnule segment. The disk is lacking. The 

 color in formalin is white. Dr. Gislen remarked that this specimen comes closest to 

 Catoptometra hartlaubi from which it differs in the occurrence of an opposing spine and 

 in the pinnules which, compared with the arm length, are somewhat longer. 



In the specimen from Mortensen's station 5, as described by Gislen, the cirri are 

 XXXII, 14-16, from 11 to 15 mm. long. The penultimate segment bears an indistinct 

 opposing spine. Ihe 23 arms are 80+ mm. long. Of the 10 IIBr series eight are 

 4(3+4) and two are 2(1 +2). Of the five IIIBr series three are 4(3+4) and two are 3, 

 both of the last on a IIBr 2 series. With 10 IIBr and five IIIBr series present the 

 number of arms must be 25 instead of 23, as given by Gislen. The distal border of 

 the brachials is rather strongly everted and serrate. The distal intersyzygial interval 

 is five or six, or eight, muscular articulations. The pinnule on the IIBr series is 



