UIXTACRINUS: ITS STRUCTURE AND RELATIOXS. 37 



classifications, by two of the most eminent living .authorities, both predicated 

 in part upon the insufficiencies of Wachsmuth and Springer's system, 

 and each believed by its author to be a new and correct reading of the 

 race history of the Criiioids. From such sources, and following such a 

 preface, we should not unnaturally expect a brilliant illumination of the 

 road, in search of which their predecessors have floundered in darkness. 

 But to our dismay we find that instead of celebrating a conclusive settle- 

 ment of these questions, we are only invited to witness fresh controversy. 

 For these new chroniclers do not read their history alike, and their two 

 classifications are about as diametrically and fundamentally opposite as 

 anything could be. 



Mr. Bather finds in the presence or absence of infrabasals ground for 

 a primary division of the Crinoids into two sub-classes, independently 

 developed from unknown ancestors, viz., Monocyclica and Dicyclica, of 

 which the Camerata and Inadunata are only subordinate divisions found in 

 each of the primary groups ; and he splits the Camerata in two, because he 

 thinks the Platycrinidte and their allies are too inadunate in their character- 

 istics to be allowed to remain there. 



Dr. Jaekel, on the other hand, does not recognize the dicyclic or mono- 

 cyclic base as affording ground for large divisions at all. He has a better 

 opinion of the Camerata, however, for he erects them into a sub-class under 

 the name of Cladocrinoidea, which he separates from all the other Crinoids 

 because he believes its representatives descended independently from 

 some of the many-plated Cystids ; and the Platycrinoids he firmly retains 

 within tliis group. The remainder of the Crinoids he groups in a sub-class 

 of equal rank with the Camerata, under the name Pentacrinoidea, within 

 which are to be found the Fistulata (W. & Sp.), Larvata (Larviformia 

 W. & Sp.), Costata, Articulosa (Articulata W. & Sp.), and Articulata {senm 

 Job. Miiller). Monocyclic and dicyclic forms occur indiscriminately through- 

 out each of his basic groups. 



While, therefore, we may adtnire the boldness and skill of these two 

 distinguished adventurers upon the stormy sea of speculation, and may await 

 with '"interest" the survival of one or the other of the antagonistic conclu- 

 sions to w'hich their phylogenetic excursions have led them, others of us, 

 who have not felt quite ready to embark, may perhaps content ourselves 

 yet awhile with paddling along close to the shore, however " uninteresting " 

 our modest venture? may be. 



