MONOGRAPH OF THE EXISTING CRINOIDS. 3 



the entire collection brought together by the Royal Indian Marine Surveying steamer 

 Investigator, as well as the other collections belonging to the Indian Museum, collec- 

 tions remarkable for their unusual completeness. 



The large and extensive collections of West Indian crinoids made by the ships 

 of the United States Bureau of Fisheries and deposited in the United States National 

 Museum were now studied in connection with the East Indian material, having been 

 up to this time laid aside awaiting the publication of the report upon the Blake 

 collection of 1878-'79 by Dr. Clemens Hartlaub. 



The Berlin Museum, through Drs. W. Weltner and R.Hartmeyer, now submit ted 

 to me their entire crinoid collection, an act of courtesy the importance of which to 

 me can only bo realized when it is remembered that this collection contains the types 

 of very many of the species described by Prof. Johannes Miiller and by Dr. Clemens 

 Hartlaub ; and Doctor Mortensen sent me a magnificent collection of Arctic material, 

 undoubtedly the finest in existence, together with the specimens which he himself 

 had collected while in the West Indies. 



At this time the Australian Museum, through Dr. Robert Etheridge, jr., its 

 curator, sent me for study their entire collection of Australian crinoids, numbering 

 nearly one thousand specimens. 



The Albatross was now engaged in an exhaustive survey of the marine resources 

 of the Philippine Islands, and the crinoids which she obtained were, as fast as they 

 accumulated, turned over to me by the Bureau of Fisheries. 



Two summers were spent at the Museum of Comparative Zoology at Cam- 

 bridge, Massachusetts, working in the library and studying the fine collections of 

 crinoids there, which are especially important in containing a number of species 

 from the Challenger dredgings, named by P. II. C'arpenter. Every courtesv was 

 extended to me, and I was very materially assisted in my work by Mr. Alexander 

 Agassiz, the director of the University Museums, Mr. Samuel Hcnshaw, the Curator 

 of the Museum of Comparative Zoology, and by Dr. Hubert Lyman Clark, the 

 assistant in whose care is the collection of echinoderms. I was also fortunate in 

 having the constant companionship and friendly advice of Prof. Robert Tracy 

 Jackson, of Harvard College, who was at that time engaged in the preparation of 

 his monograph of the palaeozoic echinoids. 



The collections and library of the Boston Society of Natural History were fre- 

 quently consulted, for which privilege I am indebted to Dr. Glover Merrill Allen 

 and to Mr. Charles W. Johnson. I also visited the Peabody Museum at Yale 

 University, New Haven, Connecticut, where I enjoyed the advantage of reviewing 

 the material with Prof. Addison E. Yen-ill; and the museum of the Essex Institute 

 at Salem, Massachusetts, of which Prof. Edward S. Morse is the director. 



During the summer of 1910 I spent four months in Europe studying the collec- 

 tions in the various museums, paying particular attention to the types of previous 

 authors; I visited Bergen, Christiania, Stockholm, Copenhagen, London, Lcyden, 

 Brussels, Paris, Lyons, Berlin, Hamburg, Dresden, Prague, Yienna, Graz, Monaco, 

 Genoa and Naples. 



After my return to Washington the Copenhagen Museum most kindly sent to 

 me the large and important Ingolf collection; the Berlin. Museum, through Pro- 



