IV CONTENTS. 



Number 20. 



Page 



Art. X. — Tamiobatis vetustus ; a new Farm of Fossil Skate ; 



by C. R. Eastman. (With Plate I.) _ 85 



XI. — Florencia Formation ; by O. H. Hershey 90 



XII. — Native Iron in the Coal Measures of Missouri ; by E. 



T. Allen . . _ _ . _ _ I . . . 99 



XIII. — Bixbyite, a new Mineral, and Notes on the Associated 



Topaz; by S. L. Penfield and H. W. Foote __ 105 



XIV. — Composition of Ilmenite ; by S. L. Penfield and H. 



W. Foote 108 



XV. — Separation of Aluminum and Beryllium by the action 



of Hydrochloric Acid ; by F. S. Havens. Ill 



XVI. — Igneous Rocks of the Leucite Hills and Pilot Butte, 



Wyoming; by W. Cross ._ 115 



XVII.— Stylolites; by T. C. Hopkins. 142 



XVI1L— Extinct Felidse ; by G. I. Adams 145 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Electrical Convection of certain Dissolved Substances, 

 Picton and Linder, 150. — Phenomena of Supersaturation and SupercooliDg, 

 Ostwald : Therrnochemical Method for determining the Equivalents of Acids 

 and Bases, Berthelot. 151. — Action of Potassium and Sodium vapor in color- 

 ing the Haloid salts of these metals, Giesel : Action of the Silent Electric Dis- 

 charge on Helium. Berthelot, 152. — Further Note on the Influence of a Mag- 

 netic Field on Radiatioo Frequency, Lodge and Davies, 153. 



Geology and Mineralogy — Recent publications of the U. S. Geological Survey, 155. 

 — Pleistocene Features and Deposits of the Chicago Area, F. Leverett, 157. — 

 A new fossil Pseudoscorpion, H. B. Geinitz: Catalogus Mammalium tarn viven- 

 tium quam fossihum, E.-L. Trouessart : Brief Notices of some recently 

 described Minerals, 158. — The Bendego Meteorite, O. A. Derby, 159. 



Miscellaneous Scientific Intelligence — American Association for the Advancement 

 of Science, 160. — Development of the Frog's Egg, an Introduction to Ex- 

 perimental Embryology, T. H. Morgan, 161. 



Obituary — Alfred M. Mayer, 161. — A. Des Cloizeaux: Julius Sachs, 164. 



