122 F. A. Bather — On Ajnocrinus from the Muschelhalk. 



little-known form, which, in any case, has nothing to do with 

 tlie present species. From Encrinus this differs in its uniserial 

 arms, its narrow conical calyx, and minor characters. From 

 Uolocrinus and Pentacrinus it differs, if in nothing else, in the 

 total absence of cirri. It might be regarded as a young Dadocrinus 

 were it not for the absence of all expansion in the radial circlet, 

 the conical enlargement of the proximal columnals, and perhaps the 

 tenuity of the pinnules, especially the proximal one, which in 

 Dadocrinus is relatively large, retaining more than the other 

 pinnules a memory of the time when it was a full-grown 

 arm-branch. The position of brachial syz3'gies, however, accords 

 fairly with what we know of Dadocrinus, except for their occasional 

 occurrence in the more distal regions of the arm. 



Turning to pre-Triassic Inadunate crinoids, there is no reason to 

 suppose that they contain a congener of our fossil : the apparent 

 regularity of the cup, the absence of any anal plates or anal tube 

 (inferred from the space occupied by the radials in the portion 

 exposed and from the absence of any remains of an anal extension 

 of the tegmen), and the non-appearance of infrabasals, all disincline 

 one to place it with the Palaeozoic Inadunata. 



We look, therefore, to the Mesozoic crinoids, and among them 

 we must, I think, confine ourselves to the pseudo- monocyclic 

 descendants of the Inadunata. There is no reason for instituting 

 a comparison with such totally different forms as Bonrguelicrinns, 

 Rhizocrinus, Eugeniacrinus, or their allies. From the Pentacrinidse 

 this crinoid is removed by the abseiice of cirri, and we are thus 

 restricted to the Apiocrinidae. 



The family Apiocrinidas is that to which Dr. Crema has referred 

 his new species, but his reference of it to Ajnocrinus is opposed by 

 the details now manifest. It is clear, as shown above, that the 

 primibrachs of each ray were not united by close suture either to the 

 radials, or to each other, or to the primibrachs of the adjacent rays ; 

 but these are, as Dr. Crema fully recognizes, the chief characters 

 distinguishing Apiocnnus and Guettardicrinns from Millericrinvs. 

 Not that this species is a very typical Mill ericrinns either. The 

 proximal cone of the stem undoubtedly suggests the Apiocrinidse, but 

 the proximal columnal itself has neither the full development nor 

 the regular shape, with "five salient crests," that would entitle it to 

 De Loriol's name, " article basal." It is true that the proximal 

 columnal of Apiocrinidas may abnormally be imperfect, as in 

 Millericrinus Pratti (see P. H. Carpenter, Quart. Journ. Geol. Soc, 

 vol. xxxviii, p, y3) ; but that does not make the present structure 

 any evidence in favour of Apiocrinid affinities. The columnals below 

 the cone are, as a rule, in Apiocrinidte of less height than those of 

 the cone ; but here they are higher. The basals are higher in 

 proportion to their own width, and to the height of the radials, than 

 the3' are in any Millericrinus earlier than the globose and peculiar 

 species of the Sequanian, such as M. flauriausianus. In fact, the 

 height of the radials also, and the height of the cup generally, are 

 not quite in keeping vvith Millericrinus, which, like all Apiocrinidee, 



