1885.] NATURAL SCIENCES OP PHILADELPHIA. 225 



REVISION OF THE PAL.EOCRINOIDEA. 

 BY CHARLES WACHSMUTH AND PRANK SPRINGER. 



Part III. 



DISCUSSION OF THE CLASSIFICATION AND RELATIONS OF 



THE BRACHIATE CRINOIDS, AND CONCLUSION 



OF THE GENERIC DESCRIPTIONS. 



Introductory Remarks. 



During the five years that have elapsed since the publication 

 of the first part of this work, great progress has been made in 

 the study of the Crinoids, both recent and fossil, and many new 

 and interesting forms have been discovered and described. 



A number of publications have appeared, "which must be 

 regarded as among the most important contributions that have 

 ever been made to the literature of the subject. During the 

 course of our studies for the present paper, we have had the 

 benefit of these discussions and researches, in many instances 

 through the personal kindness of our scientific friends. We have 

 been especially favored in this respect by receiving from Dr. P. 

 Herbert Carpenter many of the proof-sheets of plates and text, 

 in advance of publication, of his magnificent work on the Crinoids 

 of the Challenger collections. This has been of the utmost value 

 to us, and we feel that we cannot be too grateful to the distin- 

 guished author for his courteous attention. 



We may be pardoned for alluding to the satisfaction we have 

 felt at the kind reception our work has met, at the hands of our 

 co-laborers both in this country and in Europe. That our views 

 would encounter criticism, was expected, and indeed desired by 

 us. The criticisms have for the most part been made in a true 

 scientific spirit, with a view to elucidating the truth. They have 

 in many cases been of value to us, and have enabled us to review 

 the questions raised in a new light. As a matter of course errors 

 on our part have been discovered and pointed out. 



In the meantime we ourselves have learned a great deal more 

 about Crinoids than we knew at the time we wrote our first part, 

 independently of the discussions and criticisms above referred 

 to. We have now a far more complete collection of the literature 



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