IV CONTENTS. 



Number 224. 



Page 

 Art. VIII. — A Study of Some American Fossil Cycads. Part 

 VII.-— Further Notes on Disk Structure ; by G. R. 

 Wi eland _ _ 11 V 



IX. — Separation of Zirconium from Iron and Aluminum with 

 the Aid of the Ammonium Salt of Nitrosophenylhy- 

 droxylamine (" Cupferron ") ; by W. M. Thorjston, 

 Jr., and E. M. Hayden, Jr 137 



X. — Crystal Form of Some of the Hydrated Halide Salts of 



the Alkali Metals ; by C. W. Cook _ 142 



XI. — Dinosaurs not a Natural Order ; by F. R. von Huene 145 



XII.— Possible Method of Ruling Used by Nobert ; by J. M. 



Blake _ _ 147 



XIII. — Observations on the Crown Structure of Psaronius 



Braziliensis ; by O. A. Derby 149 



XIV. — Nodules with Fishes from the Coal Measures of 



Kansas ; by W. H. Twenhofel and C. O. Dunbar ._ . 157 



XV. — Empressite, a New Silver-Tellurium Mineral from 



Colorado; by W. M. Bradley 163 



XVI. — New Volumetric Method for the Determination of 



Sulphurous Acid ; by G. S. Jamieson 166 



XVII.— Relativity and the Ether; by L. Page.. _.. 169 



SCIENTIFIC INTELLIGENCE. 



Miscellaneous Scientific Intelligence — La Methode Universelle de Fedoroff, 

 W. W. Nikitin: Les Hypotheses Cosmogoniques Modernes, A. Veronnet: 

 La Forme de la Terre et sa Constitution Interne, A. Veronnet: Mono- 

 graph of the Shallow-water Starfishes of the North Pacific Coast, from the 

 Arctic Ocean to California, A. E. Verrill, 188. 



