214 THE VOYAGE OF H.M.S. CHALLENGER. 



uame implies, really consists, either wholly or partially, of united basals, the composition 

 of the calyx is the same as in Holopus and Cijathidium, in fact as in most Neocrinoids, 

 few of which are dicyclic. In all cases of which we have full knowledge, the basals rest 

 upon something representing a stem, the special organ which is so characteristic of the 

 Crinoids. It may perhaps be only a central abactinal plate, which becomes transformed 

 into an expanded disk of attachment, as in the Pentacrinoid larva of Comatula. But I 

 strongly suspect on general morj^hological grounds that the basal element in the cup of a 

 Crinoid does not come into dii-ect contact with the supporting surface ; and I have an 

 equally strong suspicion that it is never entirely absent. The radials of all Crinoids, 

 excepting the ordinary Comatulse, rest in fossae which are separated by interradial ridges 

 that mark the median lines of the united basals (PL XX. figs. 2, 3). Such ridges occur 

 in Cotylecrinus, the raised angles of the upjjer edge of the cupule being interradial in 

 position ; ^ and I am therefore disposed to agree with Zittel in regarding them as belong- 

 ing to basals, the lower limits of which are as yet unknown. 



There is another character, besides the symmetrical radials, in which Cotylecrinus 

 resembles Cyathidium. This is the association of two or more individuals in a manner 

 suggestive of a process of budding, both internal and external. Steenstrup noticed this 

 pepuliarity in Cyathidium, and de Loriol has described it in Cotylecrinus miliaris} This 

 last species is further remarkable from the fact that the outer surface both of the cup and 

 of the second radials found associated with it, " est couverte de petites pustules, tantot un 

 peu ecartees, tantot, au contraire, tres serrdes." These at once retail the blunt tubercles 

 of Holopus (Pis. L, IL). 



Cotylecrinus, Cyathidimn, and Holopus are evidently very closely alhed, though the 

 two former differ from the latter in the symmetry of their radials. 



In the remarkable form, which after having been referred to Plicatocrinus and also 

 to Eugeniacrinus, has been made the type of a new genus Eudesicriniis by de Loriol, 

 there are, however, five asymmetrical radials. These rest " sur uue base large, assez 

 elevee, adherente par un epatement anx corps soumarins. Cette base n'est point une 

 piece centro-dorsale semblable a celle des Cotylecrinus, renfermant les parties molles de 

 I'animal, c'est un simple support." The radials of this type are much higher than those 

 of Cotylecrinus, and enclose a less extensive space in the centre of the funnel which they 

 form by their apposition. It narrows considerably below, however, and I question very 

 much whether it contained more than quite a small portion, if any, of the digestive 

 canal. But according to de LorioP " c'est done dans la cavite formee j)ar les pieces radiales 

 que se trouvaient logees les parties molles de I'animal." I suspect, however, that the greater 

 part of the visceral mass lay above the surface of the cup, and was protected by the two 

 outer radials and lower arm-joints, just as in Rhizocrinus and Bathyco-inus (PI. VII. 

 figs. 2, 3 ; PL IX. figs. 1, 3 ; PL X. fig. 20). 



1 Palcout. Franj., loc. cit., yl 20, figs. 1, 2, 5, G. - Ihid., p. 204, pi. 19, tigs. 15, 17. ^ jjjy.^ p. gg. 



