IV 



CONTENTS. 



-^ *i\ 



& 4 



Number 230. 



Page 

 Art. VIII. — The Igneous Origin of the "Glacial Deposits" 

 on the Navajo Reservation, Arizona and Utah ; by H. E. 

 Gregory - 97 



IX.— The Energy of a Moving Electron ; by L. Page 116 



X. — A New Nebraska Mammoth, Elephas hayi ; by E. II. 



Barbour - 129 



XI. — A New Gavial from the Late Tertiary of Florida ; by 



E. H. Sellards 135 



XII. — Chlamytherium septentrionalis, an Edentate from the 



Pleistocene of Florida ; by E. H. Sellards 139 



XIII. — Bournonite Crystals of Unusual Size from Park City, 



Utah ; by F. R. Van Horn and W. F. Hunt 145 



XIV.— The Age of the Castile Gypsum and the Rustler 



Springs Formation ; by J. A. Udoen ._ 151 



XV. — On the Determination of Lead as Sulphite ; by G. S. 



Jamieson 157 



XVI. — The Crystallization of Haplobasaltic, Haplodioritic 



and Related Magmas ; by N. L. Bowen 161 



XVII. — The Migrations and Geographic Distribution of the 



Fossil Amphibia ; by R. L. Moodie. 186 



XVIII. — The Microscopical Characters of Volcanic Tuffs — 



a Study for Students ; by L. V. Pirsson 191 



XIX. — Northfieldite, Pegmatite, and Pegmatite Schist ; by 



B.K.Emerson 212 



SCIENTIFIC INTELLIGENCE. 



Geology and Mineralogy — Water Eeptiles, Past and Present, S. W. Willi- 

 ston: Illinois Coal Mining Investigations. 217. — Topographic and Geologic 

 Survey of Pennsylvania, R. E. Hice : West Virginia Geological Survey, 

 I. C. White : Wisconsin Geological and Natural History Survey, E. A. 

 Birge, 218. — Geological Survey of New Jersey, H. B. Kummel : Native 

 Silver in Glacial Material at Columbia. Mo., W. A. Tarr : Mineral Re- 

 sources of New Mexico, F. A. Jones, 219. — Geological Investigations in 

 the Broken Hill Area, D. Mawson : The Turquoise ; A Study of its His- 

 tory, Mineralogy, Geology, Ethnology, Archaeology, Mythology, Folklore 

 and Technology, J. E. Pogue : Chiastolites from Bimbowrie, South 

 Australia, D. Mawson, 220. 



Miscellaneous Scientific Intelligence — Ancient Hunters and Their Modern 

 Representatives, W. J. Sollas, 220. — Insects and Mau, C. A. Ealand, 

 221: Thirteenth Report on the Sarawak Museum, 1914, J. C. Moulton, 222. 



Obituary — Dr. Joseph A. Holmes, 222. 



