CONTENTS 



Original Papers 



Page 



Radiotelegraphy. — The measurement of received radiotelegraphic signals. 

 L. W. Austin 133 



Mineralogy. — A danger to be guarded against in making mineral separations 



by means of heavy solutions. W. F. Hillebrand 137 



Two varieties of calciovolborthite (?) from eastern Utah. W. F. Hille- 

 brand and H. E. Merwin 138 



Botany. — Ivory palms in Panama. O. F. Cook 138 



A new genus of davallioid ferns. VVm. R. Maxon 143 



Helminthology. — Draconema: A remarkable genus of marine free-living 

 nematodes. N. A. Cobb , 145 



Abstracts 



Physics 150 



Mineralogy 151 



Economic Geology 152 



Heredity 152 



Proceedings 



The Washington Academy of Sciences 154 



The Anthropological Society of Washington 155 



The Geological Society of Washington 156 



