A MONOGRAPH OF THE EXISTING CRINOIDS 321 



In the specimen from Blake station 241 the number of the pure white cirri is about 

 XXX, in that from Blake station 272 about XX. The segments, except for the first 

 three or four, are elongated. The cirri are entire only in the specimen from Blake 

 station 272, in which they have 18-20 segments of which the 8 outermost have processes 

 on the distal ends and the penultimate bears an opposing spine. 



In the smaller specimen from Blake station 272 the radials, although withdrawn, 

 are visible, but they are almost entirely concealed in the specimen from Blake station 

 241. The IBr, and IBr 2 (axillaries) are relatively flat in both; there is a marked 

 synarthrial tubercle. The axillaries are sometimes pentagonal, sometimes more 

 rhombic, but in any case without a marked posterior process. The IIB^ in the IIBr 

 2 series is rather high and rectangular. In the specimen from Blake station 241 there 

 are 8 IIBr series of which six are 2 and only two are 4(3 + 4). In the smaller specimen 

 from Blake station 272 all five IIBr series preserved are 4(3+4). In addition to the 

 IIBrseries, the specimen from Blake station 219 has one IIIBr 2 (1 + 2) series. Hereagain 

 the variation in shape of the lower brachials can be seen, the first three being rectangular 

 with transverse articulations, followed by four or five bluntly wedge-shaped with 

 diagonal articulations, then two or three transverse articulations with one or two rec- 

 tangular brachials, followed by approximately triangular brachials with strongly diagonal 

 articulations. A similar condition is seen in the lower brachials of the specimen of 

 granulifera from Martinique. 



According to Hartlaub these two specimens differ from the granulifera specimen 

 mentioned, and also from Charitometra basicurva, which has a similar brachial orna- 

 mentation, in that the elements of the division series are not smooth but ornamented. 

 In the specimen from Blake station 241 there are small more or less sharp spines or 

 dentations which are arranged along the edges, usually in a single row. In the speci- 

 men from Blake station 272, which is smaller, this ornamentation is not so well devel- 

 oped, the dentations are smaller, and blunter, though the marginal dentation of the 

 ossicles is everywhere easily recognizable. On the IBrj of this specimen the median 

 elevation is approximately in the form of a knob. It is not present in the specimen 

 from Blake station 241. The ornamentation of the first 10 to 12 brachials consists of 

 a crown of more or less high, erect, sharp teeth or spines on the distal edge which are 

 typically developed especially in the smaller specimen from Blake station 272. In 

 contrast to the first Martinique specimen of granulifera the proximal border of the 

 brachials may also be ornamented with small spines or teeth; this feature is very 

 characteristically developed on the lower brachials of some arms of the specimen from 

 Blake station 241. After the tenth or twelfth the brachials are smooth and have 

 thickened and slightly crenulate distal borders. 



Since in both specimens only a small fraction of the arms originally present are 

 preserved — in the smaller they are mostly broken off and in the larger they are re- 

 generating — only limited statements can be made regarding the original arm numbers, 

 the distribution of the syzygies, and the outer pinnules. With the regenerates the 

 number of arms in the specimen from Blake station 241 is 19, and the number in that 

 from Blake station 272 is 15. 



The sequence of the syzygies in the two fairly well preserved arms of the speci- 

 men from Blake station 272, one being an original arm from a IBr axillary and the other 

 a regenerated arm from a IIBr axillary, is as follows. In the arm from a IBr axillary 



843803—50 22 



