A MONOGRAPH OF THE EXISTING CRINOIDS 283 



figures of Ant. multiradiata Lam. (in reality of P. H. Carpenter) ( = Zygometra micro- 

 discus) given in the Challenger report on the stalked crinoids, volume 11, part 32, 1884, 

 plate 55, figures 3, 4. 



The type specimen of variipinna from Canton represents a species related to H. 

 producta from which it differs in having long spines on the outer cirrus segments in- 

 stead of a slight carination. It is also a stouter form than producta, the cirri especially 

 being stouter and longer without the distal taper seen in those of producta. The lower 

 pinnules are more cylindrical — less prismatic — than are those of producta, and the 

 spinous eversion of the distal ends of the segments is not increased at the prismatic 

 angles, but is uniform all around the dorsal side. 



So far as I can see the type specimen oi Antedon variipinna P. H. Carpenter differs 

 from the type specimen of Antedon brockii Hartlaub only in its smaller size. In both 

 specimens the disk is plated, which is most unusual in the genus Heterometra. 



History. — This species was first described by Dr. P. H. Carpenter in 1882 from a 

 specimen labeled Canton, China, in the Hamburg Museum under the name of Antedon 

 variipinna. He gave a specific formula for the species in the succeeding year. 



In the Challenger report on the comatulids published in 1888 Carpenter placed in 

 the synonymy of Antedon variipinna his Antedon crenulata described at the same time, 

 and Bell's Antedon decipiens and A. irregularis described in 1884. These last three 

 — crenulata, decipiens, and irregularis — really represent a quite different species with 

 sharply prismatic proximal pinnules bearing conspicuous processes on the distal ends 

 of the prismatic ridges of their component segments. The manuscript names Comatula 

 dubia, Antedon dubia, and Antedon bidentata published by von Graff also apply to 

 this latter species. Subsequent authors have accepted Carpenter's interpretation of 

 these forms and have without exception used the name variipinna for the species herein 

 called H. crenulata. 



In 1890 Dr. Clemens Hartlaub described Antedon brockii from a specimen col- 

 lected by Dr. J. Brock at Amboina in 1884-85, redescribing and figuring it in 1891. 



In 1910 I examined the type specimen of Carpenter's Antedon variipinna at Ham- 

 burg and was surprised to find that it was quite a different thing from the species 

 that I, following Carpenter's Challenger report, had been accustomed to consider as 

 variipinna. 



Carpenter had said in his original description that the distal ends of the cylin- 

 drical segments of the large proximal pinnules are raised into slight spines, and this 

 was found to be the case. The lower pinnules are very different from those of the 

 other forms which had been considered as synonyms of variipinna. On the other hand, 

 no characters could be found whereby Carpenter's variipinna, as represented by the 

 type specimen, could be distinguished from Hartlaub's brockii. So in the author's 

 paper on the crinoids in the Hamburg Museum published in 1912 brockii was placed 

 in the synonymy of variipinna, and from this synonymy all the various forms previ- 

 ously included were removed. 



In 1913 Dr. August Reichensperger recorded and gave notes upon numerous 

 specimens of this species which had been collected by Dr. H. Merton in the Aru 

 Islands in 1908. 



In a memoir on the echinodeims of Hongkong published in 1934 Dr. Th. Morten- 

 sen listed Amphimetra variipinna with the locality, Canton, given by Carpenter. 



