REPORT ON THE CRINOIDEA. 213 



unqnestionably very closely allied to it, but I am inclined to think that it would he 

 premature to consider them all as congeneric. 



Two other fossil genera of Neocriuoids, Cotijlecnnus and Eudedcrinus, both confined 

 to the Lias, are nearly related to Holopiis and Cyathidium, and should in my ojjinion be 

 placed in the same family. This has been generally done Avith Cotylecrinus, which is 

 perhaps better known by its older name of Cotylederma, Quenstedt. But Schliiter denied 

 its relationship to Cyathidium} which had been previously pointed out by Roemer^ and 

 Deslongschamps,^ on the ground that there are no perforated plates in Cotylecrinus. It 

 is true that Quenstedt's original specimens had no radials attached, and were therefore 

 imperforate, as were most of those figured by Deslongschamps ; but the latter author also 

 described and figured a fine specimen of Cotylecrinus docens, showing the large articular 

 surfaces of the radials, and the openings of their central canals, just as in Cyathidium. 

 This must surely have been overlooked by Schliiter, or he could scarcely have questioned 

 the relationship of the two t}^es. 



Both in Cotylecrinus and in de Loriol's new genus Eudesicrinus, the radials rest upon 

 a more or less tubular structure which is slightly expanded below and has been variously 

 described. In the former genus it has been called a stem by Quenstedt and by 

 MM. Deslongschamps,* and a top stem-joint by Schliiter.^ Zittel" suggested that t^he 

 upper part of it, which is marked by crests with intervening fossae for the reception of 

 the radials, should be considered as composed of anchylosed basals, and that the lower 

 part is a centro-dorsal ? De Loriol,^ however, considers the whole as a centro-dorsal piece, 

 not having been able to find any trace of sutures separating the upper part from the 

 lower. It is sometimes found in an isolated condition, while in other cases the radials 

 still remain in connection with it, and form a perfectly symmetrical whole, no one of 

 them preponderating in size over the others. They have only been seen in Cotylecrinus 

 docens, in which they were first figured by Deslongschamps. 



As in Holopus and in Steenstrup's Cyathidium, they correspond to the sides 

 of the pentagon, and the dorsal fossa is greatly reduced. With regard to the so-called 

 centro-dorsal of Cotylecrinus, I am decidedly of opinion that the upper portion on which 

 the radials rest represents the basals. The absence of sutures noted by de Loriol is no 

 proof to the contrary, as we know from the condition of the Palaeozoic Allageci'inus and 

 Agassizocrinus, and of the recent Rhizocrinus and Bathyciinus.^ This is in fact tacitly 

 admitted by de Loriol himself in the suggestion that the whole of the calyx tube in 

 Holopus and Cyathidium consists of anchylosed basals.^ 



If then the so-called cupule of Cotylecrinus, instead of being a centro-dorsal as its 



1 Loc. cit, p. 53. ^ Neues .lalirtucli fiir Mineralogie, 1S57, p. 817. 



3 Memoire sur la Couclie a Leptaena, Bull. Soc. Linn, de Normandie, t. iii. p. 181, pi. v. figs. 5, 6. 



■* Op. cit., pp. 174, 179. * Loc cit, p. 53. 



" Palseontologie, p. 386. ' ' Paleont. Fran{., loc. cit, p. 190. 



8 See Ann. and Mag. Nat. Hist, 1883, ser. 5, vol. xi. p. 329. ^ Paleont. Frang., loc. cit., p. 191. 



