A MONOGRAPH OF THE EXISTING CRINOIDS 131 



with 9 arms and a IIBr axillary hearing 2 arms as yet very small (listed by Hartlaub 

 as having 10 arms); this last is light brownish in color and has much elongated cirrus 

 segments. 



One of the specimens from Blake station 297 has 14 arms about 80 mm. long. 



Of the specimen^ from Blake station 294, 1 has 20 arms and 1 has between 16 

 and 20 arms. 



One of the specimens from Blake station 299 has 19 arms. 



One of the specimens from Blake station 232 has 20 arms. 



The 2 specimens from Blake station 231 included under M. C. Z., 481 have 

 between 16 and 20 arms. 



One of the specimens from Blake station 224 has 20 arms. 



Of the specimens from Blake station 269, 2 one with 17 and 1 with 18 arms 

 are small and are remarkable for the breadth of the division series which are in close 

 contact laterally and sharply "wall-sided." Of the other specimens, one has 10, one 

 14, and one 19 arms. 



The specimen from Blake station 241 is large, with 20 arms. 



Of the specimens from Blake station 259, 3 are of medium size, 1 is quite young 

 with 12 arms, and 1 is small with the rays in close lateral contact and "wall-sided." 



Of 3 specimens from Blake station 249 (M. C. Z., 27) which were not seen by 

 Hartlaub, the largest has 15 arms, one IIBr series being developed on each ray, 

 which are about 80 mm. long; the other 2 each have 20 arms which are about 50 mm. 

 and about 65 mm. long. The individual designated as M. C. Z., 406, has 19 arms. 

 Hartlaub noted that among the adult multibrachiate individuals from this station 

 some have the IBri in the closest lateral contact, while some have the IBi^ laterallly 

 free and with rounded sides. In many the lateral contact is not confined to the IBi'i, 

 but extends to the IBr 2 (axillary), the IIBr series, and the first brachials, and in some 

 of these is accompanied by a sharp flattening of the ossicles against each other. 

 Hartlaub specifically mentions the occurrence of the variety planata at this station. 



The specimens from "probably off Grenada" Hartlaub designates as variety 

 planata. 



The cotypes of Antedon pulchella, from the "West Indies," are two 20-armed 

 specimens. 



Four specimens without locality data Hartlaub regarded as especially charac- 

 teristic of the variety planata, the characteristic features of which are the slenderness 

 and breadth and sharp lateral flattening of the division series and arm bases. 



The centrodorsal is flat and discoidal, with the cirri arranged in a single marginal 

 row, XIX in the largest. 



The cirri have only 2 short basal segments. The third-sixth segments are elon- 

 gated, the fourth especially so. So far as may be judged from the cirri preserved they 

 are rather short; they are composed of about 12 segments, of which the short segments 

 in the distal half bear dorsal spines. 



The radials are concealed. The IBr and IIBr series are flattened, and their 

 component elements are very short. Because of the very close lateral contact of 

 the division series made possible by their sharply flattened sides, and their flattened 

 dorsal surface, the division series of the 5 almost horizontally extended rays taken 

 together form an almost uniform disk. There are slight synarthrial tubercles. 



