CONTENTS 



Original Papers 



Page 

 Mineralogy. — Aurichalcite from Big Cottonwood Canyon, Salt Lake County, 

 Utah. A. Ledoux 361 



Mineralogy. — The indices of refraction of analyzed rhodochrosite and siderite. 

 Edgar T. Wherry and Esper S. Larsen '. 365 



Genetics. — The role of selection in evolution. W. E. Castle 369 



Zoology. — A revision of the recent genera of the crinoid family Bourgueti- 

 crinidae, with the description of a new genus. Austin H. Clark 388 



Abstracts 



Spectroscopy 393 



Mineralogy 393 



Paleobotany 393 



Proceedings 



The Biological Society of Washington 394 



The Anthropological Society of Washington 395 



