A MONOGRAPH OF THE EXISTING CRINOIDS 231 



Prof. Ludwig von Graff in 1883 described the myzostomes from a specimen from 

 Blake station 285. These had been sent him by Carpenter, who had identified the 

 host as Actinometra lineata. 



In 1887 Carpenter mentioned the fact that in Actinometra lineata from Bahia 

 there are no traces of sacculi. 



In 1888 Carpenter described Actinometra lineata in detail, republishing the figures 

 of the centrodorsal and radials which he had given in 1880 and adding new ones. 

 The description was based on 8 specimens collected by the Challenger at Bahia. 

 He gave as additional localities for the species Blake station 285, "and possibly" 

 Blake station 155, and expressed his belief that the "Antedon, sp." described by 

 Rathbun from Brazil is identical with lineata. In addition to the technical descrip- 

 tion and systematic discussion, Carpenter in the introductory portion of his report 

 gave many notes on the centrodorsal and radials and associated structures, the 

 characteristic features of the arm division, and the position of the mouth. 



In the Challenger report Carpenter included rubiginosa among the 10-armed 

 species of Actinometra, and remarked that it had been described by Pourtales as an 

 Antedon before Antedon and Actinometra had been distinctly separated. He assigned 

 it to the Echinoptera group, characterized by having the elements of the IBr series 

 united by synarthry, and 10 arms only. Within this group he placed echinoptera, 

 meridionalis, pulchella, rubiginosa, and blakei (MS.). He mentioned that IIBr 4 

 (3 + 4) series "occasionally occur in Actinometra rubiginosa," so that evidently he 

 had discovered that Pourtales' type has 11 arms instead of 10 as stated in the orig- 

 inal description, as in the habitat he gave for rubiginosa he mentioned only the 

 localities given by Pourtales. 



Carpenter said in the Challenger report that he did not know for certain of any 

 Atlantic representative of the Parvicirra group, though there is possibly one on the 

 Brazilian coast. He referred to the small specimens of Nemaster rubiginosa described 

 by Rathbun. 



In 1900 Dr. Hubert Lyman Clark, misled by Pourtales' description and Car- 

 penter's disposition of the type in the Challenger report, recorded Comactinia echi- 

 noptera under the name of Actinometra rubiginosa from Porto Rico. 



On Carpenter's death the Blake collection of comatulids was turned over to Di. 

 Clemens Hartlaub, whose memoir upon them was published in 1912. 



Hartlaub considered all of the American comasterids excepting Actinometra 

 [Comatonia] cristata, the habitat of which was unknown to him, as representing 

 varieties of Actinometra [Comactinia} echinoptera. He found that Pourtales' specimen 

 from the Bahamas, instead of having 10 arms as described by Pourtales, in reality 

 has 11, one IIBr 4 (3 + 4) series being present, while the arm fragments from the 

 Tortugas are quite like the arms of Carpenter's lineata. 



He considered that rubiginosa represented a variety of echinoptera very close 

 to var. carinata (Leptonemaster venustus), and also to var. meridionalis (a shallow water 

 form of Comactinia echinoptera}, but in the other direction he considered it allied with 

 var. discoidea (Nemaster discoidea) through the possession of a IIBr 4 (3 + 4) series. 



He remarked that if Carpenter's description of lineata be compared with the 

 characters of the type specimen of rubiginosa and with the arm fragments noted by 



