RE VIE IV S 541 



"Stammesgeschichte der Pelmatozoen," the first part of which, 

 embracing the Thecoidea and Cystoidea, has just been published. 

 He, likewise, finds fault with Wachsmuth & Springer, because, in his 

 opinion, they have dealt with the morphological conditions as they 

 found them too much from an anatomical standpoint, and have not 

 sufficiently taken into account the import of the modifications due to 

 descent. He finds in the changes in the systematic arrangement of 

 the crinoids made by Wachsmuth & Springer in their successive 

 writings, proof that the right road to the solution of the great ques- 

 tions of classification had not yet been found. We have, therefore, 

 two new and almost simultaneous phylogenetic classifications, by two 

 of the most eminent living authorities, both predicated in part upon 

 the insufficiencies of Wachsmuth & Springer's system, and each 

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

 history of the crinoids. 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 settlement 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." 



Uintacrinus presents a striking resemblance to the living crinoid 

 iVctinometra in the eccentric position of its mouth, the central position 

 of the anus, the absence of any calcified ambulacral skeleton on disk, 

 arms and pinnules, the structure and distribution of the disk ambu- 

 lacra, the form and proportions of brachials, and distribution of 

 syzygies, the variable size of the anal tube, and the instability of the 

 base. 



The systematic position of Uintacrinus will be a matter of contro- 

 versy for a long time to come. As yet hardly any two authorities 

 agree in placing it in the same position. 



Wherever it may belong, and whatever its line of descent, there is no 

 doubt that Uintacrinus is both a protean and convergent form more remark- 

 able than any we have hitherto encountered amon^ the crinoids. Along with 

 great variability in the base and interbrachial regions, it combines : 



The interbrachial system and fixed pinnules of the Camerata ; 



The pliant test of the Flexibilia ; 



The large visceral cavity of both of these ; 



