A MONOGRAPH OF THE EXISTING CRINOIDS. 



By AUSTIN HOBART CLARK, 



Assistant Curator, Division of Marine Invertebrates, United States National Museum. 



PREFACE. 



HISTORY OP THE WORK, WITH AN ACCOUNT OF THE MATERIAL STUDIEn. 



Upon the return of the United States Fisheries steamer Albatross from her 

 cruise in 1906 through the Bering Sea and in Asiatic Russian and Japanese waters, 

 during which I accompanied her as acting naturalist, the Commissioner of Fisheries, 

 Hon. George M. Bowers, very kindly intrusted to me the work of identifying and 

 describing the Crinoidea which had been collected. 



The aim of the work as originally planned was the preparation of a memoir 

 dealing only with the specimens collected on tliis cruise, but it was later suggested 

 that I include in my study the crinoids from the North Pacific which had previously 

 been collected by the Albatross, and had been deposited in the United States National 

 Museum. 



The work proved to be far more of an undertaking than had been anticipated; 

 so great was the number of new species and so radically did they alter the conception 

 of the recent representatives of the Crinoidea as a whole that I was at last forced to 

 begin at the beginning and to review critically the whole subject. 



The two great monographs of Dr. Pliilip Ilerbert Carpenter were, of course, the 

 foundation upon wliich I expected to build; but, with the enormous mass of material 

 at hand, I soon discovered that the subject must be approached along somewhat 

 different lines from those by wliich it was approached by Carpenter, especially in 

 regard to the cornatulids. I therefore laid aside the literature and, with nothing but 

 the specimens before me, attempted to elucidate the systematic problems presented 

 with a mind free from preconceived ideas. The specimens were grouped into species 

 and the species into tentative genera, and these genera again into tentative families, 

 upon characters, both external and internal, which I myself determined; when my 

 ideas had become sufficiently crystallized I again took up the study of the literature 

 and compared my results with those of Carpenter. 



Up to this time the work had all been based upon north Pacific species from the 

 Asiatic and American coasts. Radical systematic revision based upon material from 

 a limited district only has seldom proved long lived, and I was therefore extremely 

 anxious to examine additional collections in order to test my conclusions and to 

 investigate further many problems connected with geographic, bathymetric, and 



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