466 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



In 1862 Dujardin and Hupe published a translation of Miiller's original descrip- 

 tion, but omitted the color, size, and locality. 



Dr. P. H. Carpenter in 1879, after an examination of the type specimen in the 

 Paris Museum, listed articulata as a member of tne genus Antedon as understood 

 by him and mentioned the occurrence of IIBr 2 and IIIBr 2 series. 



In 1882 Prof. F. Jeffrey Bell published a specific formula for Antedon articulata 

 and also for a new species, which he called Antedon reginae. These specific formulae 

 were criticized and emended by Carpenter early in 1883. 



In the Alert report published in 1884 Professor Bell recorded Antedon articulata 

 from Port Molle without comment and also described and figured Antedon reginae, 

 which was likewise from Port Molle. 



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

 Bell's formula for Antedon articulata and mentioned the peculiarities of its arm division. 

 In the key to the species of the Palmata group articulata was paired with the new 

 species regalis, both of them having P 2 and P 3 about equal in size. It was separated 

 from regalis by having the cirri with 35-40 segments, the later distinctly spiny, 

 whereas in regalis there are 25-30 cirrus segments, the later ones with pointed keels, 

 and the lower brachials are flattened. In his description of Antedon regalis Carpenter 

 said that this fine specimen (the type specimen) is not unlike Antedon articulata but 

 has a smaller number of cirrus segments, with less well defined spines than occur 

 in that species. In fact, the spines are hardly anything more than a small pointed 

 process in the middle of the sharp dorsal keel. The fourth pinnule is relatively smaller 

 and the second syzygy nearer the disk than in the type of Antedon articulata; and there 

 are less than 30 arms instead of nearly 40, or even more, as palmar (IIIBr) auxiliaries 

 are not always developed, and there are no postpahnar (IVBr) series at all. 



Carpenter remarked that Bell's Antedon reginae was represented by a single 

 specimen with 38 arms. He said that from his experience with Comanthus parvitirra 

 he could quite believe it possible that examples may eventually be found in which 

 there are no IIIBr series and so not more than 20 arms. In his key to the species of 

 the Palmata group reginae was placed under the headings P a present, two or more 

 axillaries beyond the IBr series, P 2 larger than P 3 , the postradial series in close con- 

 tact laterally, and the cirri spiny. It was distinguished from gyges and palmata 

 through having P 2 not greatly larger than P 3 , no IVBr series, and the first syzygy 

 between brachials 5+6 in arms that arise from a IIBr axillary. In gyges and palmata 

 P 2 was given as considerably longer than P 3 , IVBr series are present, and the first 

 syzygy is always between brachials 3+4. The locality for reginae he gave as 

 Queensland. 



Hartlaub in 1891 included articulata and reginae in his key to the species of 

 the Palmata group, taking the differential characters from Carpenter's earlier key. 



In my first revision of the old genus Antedon published in 1907 I referred articulata 

 and reginae to the new genus Himerometra, and in the revision of the family Himero- 

 metridae published in 1909 I referred both to the new genus Dichrometra. 



In a paper on the crinoids of the Paris Museum published in 1911 I redescribed 

 the type specimen of Miiller's Comatula (Alecto) articulata. 



In my memoir on the recent crinoids of Australia published in 1911 I admitted 

 as valid species both Dichrometra reginae and D. articulata. In the key to the species 



