CONTENTS TO r OLTJME XY. 



Numlber 85. 



Page 



Art. I. — Morphogenesis of Platystrophia. A Study of the 



Evolution of a Paleozoic Brachiopod ; by E. R. Cumings 1 



II. — Ruling Concave Gratings ; by W. Rollins 49 



III. — Variation of Potential along a Wire Transmitting 



Electric Waves ; by C. A. Chant . _ _ _ 54 



IY.— Rickardite, a New Mineral ; by W. E. Ford . _ 69 



V. — Occurrence of Free Phosphorus in the Saline Township 



Meteorite ; by O. C. Farrington . _ V 1 



Ogden Nicholas Rood __. 73 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Properties of Eadium, Giesel : Eadio-activity of 

 Uranium, F. Soddy, 78. — Eadio -activity of Thorium, Eutherford and 

 Soddy : Metallurgical Laboratory Notes, H. M. Howe : Analysis of Steel- 

 works Materials, Brearley andlBBOTSON, 79. — Electro- chemical Analysis, 

 E. F. Smith : Potash Salts, L. A. Groth : Elektro-Metallurgie, W. 

 Brochers : Physikalische Chemie der Zelle und der Gewebe, E. Hober : 

 Electrical Properties of Thin Metal Films, J. Patterson, 80. — Formation 

 of Ozone by Electrical Discharges in Oxygen, E. Warbury : Examination 

 of Spectroscopic Methods, H. Konen : Does Motion through the Ether 

 cause Double Eefraction ? Eayleigh : Scientia, Serie Physico-Mathe- 

 matique ; No. 19, L'Electricite' deduite de l'Experience, E. Carvallo, 

 No. 20, Sur les principes fondamentaux de la Theorie des Nombres et de la 

 Geometrie, H. Laurent, 81. — Lehrbuch der Physik, 0. D. Chwolson, 82. 



Geology and Natural History — New Mineral Names, 82. — New Forms on 

 Sperrylite, Goldsmith and Nicol : Eecherches geologique et petro- 

 graphique sur l'Oural du Nord dans la Eastesskaya et Kizelowskaya-Datcha 

 (Perm, Eussie), L. Dtjparc et F. Pearce, 83. — Mineralogy, H. A. Miers, 

 84. — Zur Fossilen Flora der Polarlander, A. G. Nathorst : Beitrage zur 



• Kenntniss einiger Mesozoischen Cycadophyten, A. G. Nathorst, 85. — Flora 

 of the South Fork of Kings Eiver, A. Eastwood, 86. — Botanical Survey 

 of San Jacinto Mountain, H. M. Hall, 87. 



Miscellaneous Scientific Intelligence — Development and Evolution, including 

 Psychophysical Evolution, Evolution by Orthoplasy, and the theory of 

 Genetic Modes, J. M. Baldwin, 88. 



