A MONOGRAPH OF THE EXISTING CRINOIDS 



485 



In a fragmentary specimen from Oahu, Hawaiian Islands, recorded as brevicu- 

 neata by Hartlaub, IIIBr series are developed only on the outer sides of each postradial 

 series so that each postradial series bears six arms. This specimen is remarkable for 

 the sharply delimited bands of white and brown on the arms. 



Together with the fragments identified by Hartlaub as brevicuneata from Oahu 

 there were two specimens that Carpenter had with some hesitation separated from 

 brevicuneata. These Hartlaub recorded as similis. He said that these specimens 

 possess the features characteristic of similis, namely relatively stout lower pinnules 

 and a relatively slight difference hi length between P 3 and P4. The IIBr and IIIBr 

 series, however, are not "wall-sided" as described by Carpenter for both similis and 

 brevicuneata. The IIIBr series are developed only on the outer side of each IIBr 

 series, so that each postradial series bears six arms. Because of the fact that the arms 

 are bent back over the dorsal surface and entangled with each other, and because of 

 the numerous closely crowded cirri, the relationships of the radials and of the elements 

 of the IBr series cannot be well determined. The IBri of similis are less completely 

 visible than are those of brevicuneata. The color of the central portion of the speci- 

 mens is uniform light gray-brown ; the arms are dark brown interspersed with indi- 

 vidual lighter brachials. 



Hartlaub said that in a discussion of brevicuneata published hi 1891 he had re- 

 marked that specimens from Mortlock Island he had studied show characters inter- 

 mediate between those of brevicuneata and similis. He added that the eventual union 

 of the two forms is not excluded. 



The specimen from Vauna Mbalavu, Fiji, is very young, with 16 arms. 



Hartlaub said that the three specimens from Ovalau, Fiji, in the Liibeck Museum 

 that he examined show close agreement. In color two are gray-blue and one is reddish 

 brown. In all the form of the centrodorsal is the same a moderately large flat disk. 

 The cirri, of which one specimen has XLVI and both of the others XXX, are not 

 entirely confined to the margin of the centrodorsal, and are arranged in three irregular 

 rows. The opposing spine is feeble. In two of the specimens the postradial series are 

 in lateral contact, but in the third they are free. There are 38 or 39 arms. 



Dr. H. L. Clark said that the dry specimen from Fiji collected by the United 

 States Exploring Expedition seems to represent his Lamprometra brachypecha. It has 

 40 arms 65 mm. long. 



One of the specimens from Fiji in the Copenhagen Museum, labeled Antedon 

 protectus Liitken, is medium sized. The other two specimens are rather small. The 

 difference in size between the pinnules on the outer and inner arms of each postradial 

 series is not so great as usual, possibly because of immaturity. It may be that this 

 feature does not become evident until a comparatively late stage in the development 

 of the individual. 



One of the specimens from Challenger station 174 was described by Dr. P. H. 

 Carpenter as a new species under the name of Antedon similis. The centrodorsal is 

 a thick disk with marginal cirri. The cirri are about XL, 25. The segments are 

 tolerably uniform, and the later ones are compressed with a sharpened dorsal edge 

 which passes into the opposing spine. The radials are entirely concealed. The IBr! 

 are partially concealed and are closely united laterally. IIBr series are present all 

 around the calyx, and IIIBr series are present on four of the postradial series, externally 



