364 



Genus Capülaster A. H. Clark. 



Capillaster multiradiata (Linnaeus). 



A critical examination of a very large amount of material has con- 

 vinced me that to this species must be referred the Comatula fimbriata 

 of Lamarck, the Actinometra horneensis of Grube, and the Actino- 

 metra coppingeri of Bell; indeed, Carpenter himself doubted the 

 validity of the two last, and was uncertain in regard to several speci- 

 mens he tentatively assigned to the first. 



One specimen of this species was dredged by the » Gazelle at Dirk 

 Hartog Island in 7 fathoms of water; it has twenty-one arms, due 

 to the presence of two III Br 3 (2 + 3) series, developed inwardly in 

 1, 2, 2, 1 order, and the absence of one II Br series. It has six functional 

 cirri of twenty to twenty-two joints, and thirteen rudimentary cirri of 

 various lengths. The brachials are of the exceedingly short discoidal 

 type characteristic of fully developed examples. The mouth is consi- 

 derably nearer the center of the disk than usual, and the anal area 

 bears numerous scattered calcareous granules. About the margin of the 

 disk there are several large round openings leading into blind cavities, 

 usually occurring at the base of the large oral pinnules ; in the largest 

 of these cavities, which has tw^o openings, there is an ambulacral groove 

 in the interior. Were this subtegminal excavation to extend uniformly 

 under the entire disk, the result would be an internal disk, a replica of 

 the external, in other words a sort of camerate condition. This is the 

 first suggestion of a camerate tendancy to be observed among the re- 

 cent crinoids. The disk is further peculiar in possessing two mouths, a 

 supplementary mouth, not quite so large as the true mouth, being situ- 

 ated just to the right of it. 



Dr. Carpenter noted on the label that this specimen was »near 

 fimbriata«, the qualification being no doubt due to the presence of the 

 two III Br series. He mentions a similar specimen (of »fimbriata«) 

 from the Philippines, but appears to consider the condition abnormal. 

 The examination of a large series from those islands shows that III Br 

 series are usually present, at least on one ray; this, taken in connection 

 with the fact that the »discoidal« brachials appear to be solely the re- 

 sult of individual maturity, being rather more frequent in specimens 

 with more than twenty arms than in specimens with less than that num- 

 ber, prevents us from recognizing fimbriata and multiradiata as distinct 

 species. 



The arms of this specimen are 100 mm long, the cirri 15 mm; the 

 colour is light grayish brown. 



