12 ROBERT TRACY JACKSON ON ECHINI. 



Scharff, of the Science and Arts Museum, Dublin, gave me access to invaluable material, had 

 casts and photographs of M'Coy's types made, and most generously brought over to this country 

 for study one of their most valuable specimens. Dr. Otto Jaekel, recently of Berlin, kindly 

 gave me the opportunity to study his most precious specimen of Bothriocidaris, which I feel 

 is the backbone of this work. Professor A. Rothpletz and Dr. F. Broili gave me every oppor- 

 tunity to study the rich collections of the Munich Museum. At Geneva, Dr. Bedot, Director 

 of the Mus6e d'Histoire Naturelle, and Dr. Jules Favre, of the same institution, kindly gave 

 me access to their rich' collection of Recent and Mesozoic Echini, including the very valuable 

 material of the late M. de Loriol. Professor G. Steinmann and Professor G. Boehm, of Freiburg 

 i. Br., and Professor A. Tornquist, of Strassburg, placed much fine material at my disposal. 



In this country, for opportunities to study fossil Echini, I am under deep obligations to 

 many curators of museums and to private collectors. Mr. Samuel Henshaw, Curator of the 

 Museum of Comparative Zoology, kindly gave me free access to the rich collections in that 

 institution. From Professor Charles Schuchert, of Yale University Museum, besides other 

 specimens, was borrowed the superb material of Hyattechinus beecheri and rarispinus collected 

 in Warren, Pennsylvania, mostly by the late Professor C. E. Beecher. I am under similar 

 obligations to the late Professor R. P. Whitfield, of the American Museum of Natural History; 

 Dr. C. D. Walcott and Dr. R. S. Bassler, of the United States National Museum; Dr. George 

 H. Girty, of the United States Geological Survey; Professor Stuart Weller, of the University 

 of Chicago; Professor John M. Clarke, of the New York State Museum; Professor William B. 

 Clark, of Johns Hopkins University; Professor J. W. Beede, of Indiana University, who sent 

 me the remarkable new type, Meekechinus elegans and other material ; Dr. A. G. Ruthven and 

 Professor E. C. Case, of the University of Michigan; Professor R. S. Breed, of Alleghany Col- 

 lege, Meadville, Pennsylvania; Professor L. C. Glenn, of Vanderbilt University; Professor A. 

 W. Grabau, of Columbia University; and Mr. C. W. Johnson, Curator of the Boston Society 

 of Natural History. 



Of private collectors, Mr. Frank Springer generously loaned me his whole collection of 

 about 125 Palaeozoic Echini, including types and other material recently purchased from Pro- 

 fessor G. Hambach, of St. Louis. Mr. Frederick Braun, of Brooklyn, lent very choice material 

 from his private collection; and Mr. E. Kirk, now of the United States Geological Survey, lent 

 several specimens. Mr. J. E. Hyde, of Columbia University, loaned the remarkable new Lepi- 

 desthes extremis. To all these gentlemen I would render warmest appreciation for their gen- 

 erosity. The actual specimens loaned or used will be referred to as from the institution or 

 collection to which they belong under consideration of the species. 



For the opportunity to study the great collection of Recent Echini in the Museum of 

 Comparative Zoology, I am indebted to the Curator, Mr. Samuel Henshaw, and to Dr. Hubert 

 Lyman Clark, who is in charge of that department. For similar opportunities in the United 



