540 REVIEWS 



same high standard of excellence that made the Nor-th American Criti- 

 oidea Camerata of Wachsmuth & Springer so acceptable to all stu- 

 dents of fossil organisms. 



Unusual interest centers in the composition of the base of Uinta- 

 crinus. A feature that has long been regarded as fundamental in the 

 separation of the larger taxonomic groups is here found in one and 

 the same species. " Considering the apparent identity of these forms 

 in every other point of structure, coupled with their mode of occur- 

 rence and association, I do not see how such association [as made by 

 Mr. Bather] can possibly be made in this case. We therefore have 

 apparently to deal with a case of individual variation as to this sup- 

 posed primitive character, within the limits of a species. That is to 

 say, in this species, living in the same locality, having the same 

 environment, floating in the same mass, certain individuals matured to 

 represent one stage of larval development, /. <?., with infrabasals ; and 

 others in another stage, /. <?., with basals only. 



In short, there are the two supposed distinct t3'pes, Monocyclica and 

 Dicyclica, occurring in both young and adult of one and the same species. 

 It will not do to say that the species is dicyclic, but in certain individuals the 

 infrabasals are not developed, or are hidden by the centrale, or have dis- 

 appeared by atrophy. If this were so, the centrale ought to be interradial 

 in both cases ; whereas, as already shown, its orientation is reversed from 

 one to the other, precisely as in the typical monocyclic and dicyclic forms. 



Such a condition is believed to be unique among the crinoids. 

 The bearing upon certain recently proposed classifications of the 

 crinoids is also important. Bather and Jaekel have both severely 

 criticised Wachsmuth & Springer's classification and have erected 

 schemes that are " sought by the modern biologist." 



" There is no doubt," says Mr. Springer, " that each author who 

 undertakes to express his ideas of descent in a new scheme of classi- 

 fication does so in the belief that his own structure is a substantial 

 pyramid whose base is firmly established upon the ruins of the top- 

 heavy contrivances of his predecessors. With regard to the crinoids, 

 there have appeared, since our monograph of the Camerata, two 

 elaborate classifications, each avowedly based upon phylogenetic prin- 

 ciples, viz., that of Mr. Bather, already mentioned, and one by Dr. 

 Jaekel, whose general researches and great works upon the crinoids 

 of Germany constitute a rich contribution to science. The views of 

 the latter author are to be developed in full detail in his magnificent 



