NO. 15 RECENT CRINOIDS IN BRITISH MUSEUM CLARK 41 



The radials are moderate in size, resembling' those of Neometra 

 multicolor, except that they are not produced interradially, or those 

 of Ptilometra macronema. Their proximal border is marked with 

 a series of crescentic gouges in which the proximal portion of the 

 basal cirrus segments are lodged, and which represent the upper 

 part of the cirrus sockets. These last are all partly on the centro- 

 dorsal and partly on the radials ; the central canal, however, is always 

 on the centrodorsal, though it may be only slightly below its margin. 



The two elements of the TBr series appear to be united by syzygy, 

 though the union is probably by a very close synarthry ; the IBr t is 

 oblong, two and one-half to three times as broad as long; the IBr 2 

 (axillary) is broadly pentagonal, twice as broad as long; the IBr x 

 has a sharp tubercle in the middle near the .proximal border, and 

 another smaller one in the middle of its distal (anterior) margin; 

 the IBr 2 (axillary) has a tubercle in the middle of each of the two 

 distal edges ; the IIB^ and the first brachials have a median tubercle 

 on their proximal border, like the IBr x ; the IIBr 2 has a tubercle on 

 each of its distal borders, like the IBr 2 . The IBr series are broad, 

 in close lateral apposition, and slightly flattened laterally, just as in 

 Ptilometra macronema, and as in that species the component ossicles 

 are very thin dorsoventrally. The I IBr series are 4 (3 -)- 4) ; the 

 axillaries and preceding ossicles resemble those of the IBr series. 



The seventeen arms are 60 mm. long ; the brachials in general 

 resemble those of such species as Gephyrometra propinqua; as in 

 that species there is a rather sharp overlap, especially at the disto- 

 lateral angles ; the arms do not become laterally flattened distally, 

 nor carinate. 



Side and covering plates are well developed on the arms and pin- 

 nules, as is usual in the genus ; sacculi are abundant. 



The disk is lacking. 



P x is about 7 mm. long, small and weak, rather strongly prismatic, 

 flexible, with eighteen segments ; it is at first moderately stout, but 

 tapers rapidly after the proximal third, becoming exceedingly slender 

 and flagellate in the outer half ; the proximal segments are broader 

 than long, the distal slightly longer than broad ; the first segment is 

 about twice as large as the second, though it does not strike one as 

 being especially enlarged ; the second segment is also enlarged, but 

 very slightly ; it has a small dorsal carinate process, as has also the 

 third, which is not enlarged. P 2 is stiff and spine-like, 8 mm. long, 

 with ten segments, of which the first is short with a slight rounded 

 dorsal carination, though not otherwise modified ; the second is about 



