NO. 3 CASSIDULOID ECHINOIDS — KIER 3 



excellent recommendations. Dr. Richard E. Grant made many helpful 

 suggestions throughout this study, and he and Thomas R. Waller 

 edited the section on evolution. Dr. Ellis Yochelson assisted in many 

 nomenclatural problems, and I thank Dr. Norman F. Sohl for his 

 information on the Upper Cretaceous stratigraphy of the eastern 

 United States and for his large collections of specimens of Hardou- 

 inia. I am particularly indebted to Dr. G. Arthur Cooper for his 

 support of this study. The charts and the figure illustrating the 

 morphology of a cassiduloid were made by Lawrence B. Isham, scien- 

 tific illustrator. Department of Geology, U. S. National Museum, and 

 many of the photographs were taken by Jack Scott. My wife, Mary, 

 encouraged me throughout this work. 



This study would not have been possible without the assistance of 

 the many museum curators who lent specimens or made their collec- 

 tions available for study. Their generosity exceeded my highest ex- 

 pectations, and because of their help I was able to see many specimens 

 that had never been adequately described or figured, and some that 

 were presumed lost. Listed below are the names of these curators 

 and their institutions. 



Brazil 



Departmento Nacional da Producao Mineral, Rio de Janeiro: Dr. 

 Lamego, Dr. Santos. 

 Egypt 



Geological Museum, Cairo: Dr. M. Saber Mansour. 

 France 



Bordeaux : Universite de Bordeaux, Faculte des Sciences : Dr. M. Vigneuas. 



Paris: Museum National d'Histoire Naturelle : Dr. Jean Roman and 



Dr. J. Sornay. ficole National Superieure des Mines : Dr. Paul Fischer, 



and Madame Letia. Universite de Paris, Sorbonne : Dr. D. Laurentiaux. 



Strasbourg : Universite de Strasbourg, Laboratoire de Geologic et de 



Paleontologie : M. Wolf. 



French West Africa 



Dakar : Universite de Dakar : Prof. F, V. L. Tessier. 

 Germany 



Berlin: Geologisch — Palaontologisches Institut und Museum der Hum- 

 boldt — Universitiit zu Berlin: Dr. W. Gross. 

 Bonn : Geologisch-palaeontologisches Institut und Museum der Rhein. 



Friedrich Wilhelms-Universitat : Dr. Hans Mensink. 

 Alunich : Bayerische Staatssammlung fiir Palaontologie und historische 

 Geologic : Dr. Hans K. Zobelein. 

 Great Britain 



Cambridge : Sedgwick Museum : A. G. Brighton. 



Exeter : Royal Albert Memorial Museum : Dr. R. Churchill Blackie. 



Glasgow : Hunterian Museum : Dr. Ethel D. Currie. 



London: British Museum (Natural History): Dr. Leslie Bairstow. 



