466 Bl l.i i: il n B2, UNITED STATES NATIONAL MUSEUM 



I,, L862 Dujardin and 1 1 uj"' [>«il>li^ 1 »*<i a translation of Muller's original descrip- 

 tion, I'Mt omitted the color, size, and locality. 



I),. i> || Carpenter in 1879, after an examination of the type specimen in the 

 Paris Museum, listed artieulafa as a member of the genus Antedon as understood 

 by him and mentioned the occurrence of LIBr 2 and IIlBr 2 scries. 



In 1882 Prof. !•' Jeffrey Bell published a specific formula for Antnlnn articulata 

 and also for a ne\* roecies, which he called Antedon reginae. These specific formulae 

 were criticized and emended by Carpenter early in 1883. 



In the Alert report published in 1 ss-1 Professor Bell recorded Antedon articulata 

 from Porl 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 

 Hell's formula tor 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 1\> 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 arc 25-30 cirrus segments, the later ones with pointed keels, 

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

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

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

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

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

 and the second s\ zygy 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 (IIlBr) axillaries 

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



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

 specimen with Ms arms. He said that from his experience with Comanthus parvicirra 



ould quite believe il possible that examples may eventually be found in which 

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

 t! e Palmata group reginat was placed under the headings P B present, two or more 

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

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

 through having P.. 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, 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. 



Bartlaub 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 firsl n-\ ision of the old genus Antedon published in 1907 I referred articulata 

 and reginat 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 .'i paper on the crinoids of the Paris Museum published in 191 I 1 redeseribed 

 the type specimen ol Muller's Comatula {Alecto) articulata. 



In my memoir on the recent crinoids of Australia published in 1911 1 admitted 

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



