A MONOGRAPH OF THE EXISTING CRINOIDS 5 



in describing the crinoids of the 1906 cruise and that the diagnoses of many of my new 

 species were already going through the press, and he immediately insisted that I 

 take over those which had been sent to him for study along with my own much larger 

 collection. The new species given in this paper, the descriptions of which were pre- 

 pared at Cambridge, are the following: 



Bathycrinus complanatus. Antedon adrestine. 



Zygometra koehleri. Antedon minuta. 



Antedon orientalis. 



The generic name Zygometra appears in this paper for the first time, without 

 diagnosis, but used in the description of Z. koehleri, which therefore becomes the type. 

 The family name Antedonidae also appears in the text in place of the more familiar 

 Comatulidae or Comatulae. 



The second paper was a rearrangement of the comatulids previously assigned to 

 the genus Antedon, which were distributed among 18 genera, all of which, excepting 

 Antedon, were new. 



The fact is mentioned that since the publication of the Challenger monograph the 

 family Comatulidae as understood by P. H. Carpenter has been broken up into the 

 families Thaumatocrinidae (Thautnatocrinus) , Antedonidae (including Eudiocrinus, 

 Antedon, and Thiolliericrmus) , Atelecrinidae (Atelecrinus) , Actinometridae (Coma- 

 tula), and Decametrocrinidae (Promachocrinus and Decametrocrinus) . The family 

 Decametrocrinidae was found to be an unnatural combination, for Decametrocrinus 

 is most nearly related to Eudiocrinus. It is therefore rejected, and a new family, 

 Eudiocrinidae, proposed to include Eudiocrinus and Decametrocrinus. Promacho- 

 crinus is left unassigned. Minckert's Brevipinna group, a connecting link between 

 the Spinifera and Granulifera groups, is mentioned. 



The new genera proposed were the following : 



Zygometra (genotype Antedon microdiscus Bell, 1884) including 



Zygometra elegans. Zygometra microdiscus. 



Zygometra hartlaubi. Zygometra multiradiata. 



Zygometra keehleri. Zygometra rubroflava. 



Zygometra was said to correspond to Carpenter's Elegans group, or Series I of 

 Antedon, and it was recalled that Loven's genus Hyponome was based upon a detached 

 visceral mass of an unidentifiable species of this genus. 



Nanometra (genotype Antedon minor A. H. Clark, 1907) including 



Nanometra denticulata. Nanometra pusilla. 



Nanometra minckerti. Nanometra wilsoni. 



Nanometra includes those species of Carpenter's Basicurva group which lack the 

 plating of the ambulacra. 



Tropiometra (genotype Comatula carinata Lamarck, 1816) including 



Tropiometra ajra. Tropiometra braziliensis. 



Tropiometra carinata. Tropiometra macrodiscus. 



