CONTENTS 



Original Papers 



Page 

 Physics. — Determination of the zonal variation of the equivalent focus. 



E. D. TiLLYER 481 



Crystallography. — The change in the crystal angles of quartz with rise in 



temperature. Fred. E. Wright 485 



Palaeontology. — The systematic position of the Crinoid family PUcatocrin- 



idae. Austin H. Clark 494 



Abstracts 



Geodesy '. 500 



Geophysics 500 



Physics 501 



Electricity ' 501 



Physical Chemistry 501 



Geology 502 



Petrology 503 



Mineralogy 503 



Crystallography.'. '. ^ . . 504 



Botany - 504 



Zoology 504 



PROCEEDINC^S 



The Washington Academy of Sciences 505 



The Chemical Society 505 



The Botanical Society of Washington 506 



The Biological Society of Washington - 509 



The Anthropological Society of Washington , 510 



• 

 ' Announcement of Meetings 



The Washington Academy of Sciences 512 



The Nineteenth International Congress of Americanists,. .- 512 



