A MONOGRAPH OF THE EXISTING CRINOIDS 221 



I examined both these specimens from Hongkong at the Hamburg Museum in 

 1910. They undoubtedly represent the same species as the one without locality 

 that Carpenter described as Antedon acuticirra. The second specimen from Hongkong, 

 described as Antedon bipartipinna by Carpenter, has slightly smoother arms than 

 the type of A. acuticirra. 



The specimen without locality was described as Antedon acuticirra by Carpenter 

 in the following terms. The centrodorsal is a thick disk with a flat dorsal surface and 

 the cirri arranged in a single marginal row. The cirri are XV, 55, and may reach 

 50 mm. hi length. They are long and tapering and consist of smooth segments. 

 The basal segments are broad, and the tenth is about as long as broad, while those 

 following diminish in width and thickness, though the length changes but little. 

 The later ones are longer than broad but are not laterally compressed. The cirri 

 taper gradually to a sharp point. There is no trace of an opposing spine. The 

 terminal claw is small and is but slightly curved. Some of the radials are partially 

 visible, and some of the short IBr t are partly concealed. The IBi^ are closely united 

 laterally. The IBr a (auxiliaries) are nearly twice as long as the IBrj, almost triangular, 

 with open distal angles. The IIBr series are 4(3+4), and the IIIBr series are 

 usually 2, but sometimes 4(3+4). The first ossicles following each axillary are 

 closely united interiorly, and there are slight synarthrial tubercles. The 26 arms 

 are about 125 mm. long and are composed of 200+ brachials. The first brachials 

 are rhomboidal, short and broad. The second brachials are more wedge-shaped. 

 The first syzygial pair (composed of brachials 3+4) and the next four or five brachials 

 are short and oblong, the foUowing brachials are bluntly wedge-shaped, twice as 

 broad as their longer side and slightly overlapping, and the middle and later brachials 

 are more oblong and overlap rather less. Syzygies occur between brachials 3+4, 

 again from between brachials 10+11 to between brachials 17+18, and distally at 

 intervals of 6 to 33 (usually 11 to 16) muscular articulations. 



P D is comparatively small, with keeled and expanded basal segments. PI is 

 considerably larger on the outer arms but remains small on the inner ones. P a and 

 P 3 increase in size, the latter reaching 25 mm. in length and consisting of nearly 40 

 segments. P a is small like P D , and P b and P are much larger, P c approaching the 

 size of P 3 . P is somewhat smaller again, though it is still long, and the next pair 

 are a good deal shorter than their immediate predecessors, though somewhat larger 

 and stouter than P t . Where IIBr series are not present but the arms arise from a 

 IBr axillary, the fourth pair of pinnules are large like their immediate predecessors. 

 The size of the pinnules decreases to about the seventeenth brachial and then increases 

 very slowly again, the outer pinnules reaching only about one-third the length of the 

 largest lower pinnules, which have broad and strongly keeled basal segments. On 

 the smaller pinnules after the fifth pair this carination is less marked, but it is traceable 

 for some little way out on to the arms. The disk is naked and considerably incised, 

 15 mm. in diameter. Sacculi are very close along the pinnule ambulacra. The 

 color is nearly white, with traces of a deep violet remaining. 



I examined this specimen at the Hamburg Museum in 1910. The synarthrial 

 tubercles are rather prominent, and the distal edges of the brachials are rather strongly 

 overlapping. It is just like others from the eastern side of the Bay of Bengal. 



