CONTENTS. 



Number 280. 



Page 



Art. XXIV. — Further Studies of the Drainage Features of 

 the Upper Ohio Basin ; by T. C. Chamberlin and F. 

 Leykrett 247 



XXV. — An apparatus to show, simultaneously to several 

 hearers, the blending of the sensations of interrupted 

 tones; by A. M. Mayer 283 



XXVI. — Post-Eocene Formations of the Coastal Plain of 



Alabama; by E. A. Smith 285 



XXVII. — Variscite from Utah ; by R. L. Packard 297 



XXVIII. — Appendages of the Pygidium of Triarthrus; by 



C. E. Beecher. (With Plate VII) 298 



XXIX. — Geological Position of the Eocene Deposits of 



Maryland and Virginia ; by G. D. Harris _■__ -. 301 



XXX. — Contributions to the Crystallization of Willemite; 



by S. L. Penfield 305 



XXXI. — Occurrence of Olenellus in the Green Pond Moun- 

 tain Series of Northern New Jersey, with a Note on the 

 Conglomerates; by C. D. Walcott 309 



XXXII. — Notes on Nickeliferous Pyrite from Murray Mine, 



Sudbury, Ont.; by T. L. Walker.. 312 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Electric Conductivity of Flames, de Hemptixne, 314. — 

 Electrolysis of Steam. J. J. Thomson: Temperature of Ignition of Gaseous Ex- 

 plosive Mixtures, V. Meyer and Munch, 315. — Composition of Water by Vol- 

 ume, Scott, 316. — Production of Hyponitrous acid, Thum, 317. — Potassium and 

 Sodium Carbonyls, Joaxxis, 318. 



Geology and Mineralogy — International Congress of Geologists, 318. — Geological 

 Survey of the State of New York, Palaeontology, J. Hall and J. M. Clarke: 

 Alabama Geological Survey, A. M. Gibrox: Geological Survey of Texas, 1892, 

 E. T. Dumble, 319. — Outline of the Geology and Physical Features of Maryland, 

 G. H. Williams and W. B. Clark: Lehrbuch der Petrographie, Dr. F. Zirkel: 

 Geological Survey of Portugal, P. Choffat: Untersuchungen uber Fossile 

 Holzer Schwedens, H. Coxwentz, 320.— Swedish lower Paleozoic Hyolithesand 

 Conularis, G. Holm, 321. 



Miscellaneous Scientific Intelligence — British Association for the Advancement 

 of Science: History of Mathematics, F. Cajori: Ejected Blocks of Monte 

 Somma, H. J. Johxstox-Davis, 321. 



