CONTENTS. 



Page 

 Art. VII. — Ultimate Disintegration Products of the Radio- 

 active Elements. Part II. Disintegration Products of 



Uranium; by B. B. Boltwood .. 78 



VIII. — Dike of Diabase in the Potsdam Sandstone in the 



Valley of Virginia ; by T. L. Watson 89 



IX. — A Spectrum of the Rontgen Rays from a Focus Tube, 

 and the Relative Selective Absorption of Rontgen Rays 

 in Certain Metals. A preliminary note ; by J. JVI. 



Adams. (With Plate I) 81 



X. — Limeless Ocean of Pre-Cambrian Time ; by R. A. Daly 93 

 XI. — Occurrence, in the Rocky Mountains, of an Upper 



Devonian Fauna with Clymenia; by P. E. Raymond . _ 116 

 XII. — Wasatch and Wind River Rodents ; by F. B. Loomis 123 

 XIII. — Descriptions of the two genera of tubicolous Anne- 

 lids, Paravermilia and Pseudovermilia, with species from - 



Bermuda referable to them ; by K. J. Bush. ... 131 



XIV. — Titration of Mercurous Salts with Potassium Per- 

 manganate; by D. L. Randall 137 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics— Occurrence of Argon with Helium in a Mineral, 

 Kitchen aud Winterson : Researches on High Percentage Ozone Gas, E. 

 Ladenburg, 141. — Determination of Halogens in Organic Compounds, 

 Stepanow : Cause of the Phosphorescence of Chlorophane, G. Urbain, 

 142. — Comparison of the Optical Temperature Scale with the Nitrogen 

 Therraoineter up to 1600°, L. Holborn and S. Valentiner : Light Im- 

 pressions on Photographic Plates, P. H. Eykman and A. P. H. Trivelli : 

 Eatio of the Energy of the Rontgen Rays to the Energy of the exciting 

 Cathode Rays, E. Carter, 143. — Scientific Papers of J. Willard Gibbs, 

 with Preface by H. A. Bumstead and R. G. Van Name, 144. — Electron 

 Theory, E. E. Fotjrnier d'Albe, 145. — Lehrbuch der Optik, P. Drude. 



Geology and Mineralogy — Maryland Geological Survey, W. B. Clark, 146. — 

 Fifth Report of the Vermont State Geologist, 148. — Geologie und Palason- 

 tologie von Ostasien, etc. , T. Lorenz : Geology and Paleontology of the 

 Schoharie Valley, A. W. Grabau : Cephalopoda of the Beekmantown and 

 Chazy Formations, R. Rtjedemann, 148. — Geology of the Penn Yan-Ham- 

 mondsport Quadrangles, D. D. Luther : Carboniferous and Permo-Carbon- 

 iferous Invertebrata of New South Wales, E. Etheredge and W. S. Dun 

 Geology and Underground Waters of the Arkansas Valley, Colo., N. H 

 Darton : Geol. History of Mt. Greylock, T. N. Dale : Treatise on Rocks 

 Rock-weathering and Soils, G. P. Merrill, 149. — Facetted Pebbles, Lis 

 boa: Die Kristallinen Schiefer, V. Grubenmann, 150. — Rock Minerals 

 their Chemical and Physical Characters, etc., J. P. Lddings, 152. — Das 

 Salz : dessen Vorkommen und Verwertung, J. O. F. von Buschman 

 Chemische Krystallograimie, P. Groth, 153. 



Botany and Zoology — Sinnesorgane im Pflanzenreich, G. Haberlandt, 154 

 Principles of Botany, J. Y. Bergen and B. M. Davis : Second Report of 

 Wellcome Research Laboratories, Khartoum, A. Balfour, 156. — Animal 

 Micrology; Practical Exercises in Microscopical Methods, M. F. Guyer, 156. 



Miscellaneous Scientific Intelligence — Carnegie Institution of Washington, 

 Year Book No. 5, 1906, 156. — Report of the Librarian of Congress, etc., 

 1906 : Physikalische Chemie der Zelle, R. Hoeber, 158.— Differential Equa- 

 tions, D. F. Campbell : Seismological Committee, 159. — Smithsonian Insti- 

 tution : American Forestry Association : Celebration of the 200th Anniver- 

 sary of the Birth of Benjamin Franklin : Amer. Philosophical Society, 160. 



