A MONOGRAPH OF THE EXISTING CRINOIDS 47 



In a short paper published in May a new comatulid, Comissia pedinifer, was 

 described from Chiistmas Island, and a list of the known species of the genus was 

 appended, and in June the hypothetical development and inherent characters of a 

 genus were discussed. 



On June 24 two papers appeared ; in the first of these the structure of the species 

 of Comaster was considered and a new species, Comaster taviana (previously referred 

 to as Phanogenia carpenteri) was described; and in the second the reasons for believ- 

 ing Marsupites to be a comatidid and closely related to Uintacrinus are given in 

 detail. 



In August the comparative age of the recent crinoid faunas was considered on 

 the basis of the inherent characteristics of each faunal unit. 



On August 19 a paper was published on the nervous system and the symmetry 

 of the crinoids. The crinoidal nervous system is in effect composed of five interradial 

 nerves and their derivatives, each of these nerves being comparable to a single double 

 ventral nerve cord of an arthropod or annelid. The chiasmas within the axiUaries 

 appear to be repetitions of the nerve branchings within the calyx. The circumoral 

 nerve ring and the ambulacral nerves together are the equivalent of the supraoesoph- 

 ageal ganglion in the annelids or the arthropods. Each axillary is a sort of dissociated 

 radial. The five divisions of the body in the echinodcrms consist of the five inter- 

 ambulacral areas plus half of the ambulacral area on either side. The echinodermal 

 skeleton was originally merely a spicular layer developed in the mesoderm of the 

 body wall. 



The next article to appear was an account of the collection of crinoids of the Paris 

 Museum previously studied by Lamarck, J. MiiUer, and P. H. Carpenter and containing 

 types of additional species described by Guettard, d'Orbigny, Perrier, Koehler, and 

 Vaney, as well as many specimens named, though not described, by Valenciennes. 



Lamarck's Comafula rotalaria was found to be the same as the species described 

 by P. H. Carpenter asActinometrajukesii and by Bell as Adinometra paucicirra, and 

 therefore entirely different from the Adinometra rotalaria (= Comanfhus parvicirra) 

 of the Challenger report. The history of Miiller's Aledo multijida was given in detail, 

 and the type specimen was redescribed. Miiller's Aledo philiberti was found to be 

 the same as the subsequently described Amphimetra mortenseni. Bell's Antedon 

 bidens proved to be the same as Lamarck's Comatula adeonae. As was suspected at 

 the time it was described, Ptilometra dorcadis proved to be a synonym of Miiller's 

 Comatula macronema; the cirri of macronema and of the corresponding species {mulleri) 

 from southeastern Australia were figured. 



The comatulids brought back by the French scientific mission to Cape Horn 

 were described. 



The new species included were : 



Heterometra joubini. Oligometra caledoniae. 



Heterometra gravieri. Trichometra delicata. 



During a visit to Hamburg in the summer of 1910 Prof. W. Michaelsen asked 

 me to undertake the study of the crinoids which he and Dr. R. Hartmeyer had col- 

 lected in Western Australia. I had just completed a monograph on the crinoids of 



