IV CONTENTS. 



Page 

 XII. On the Optical Characters of the Vertical Zone of Amphiholes and 

 P0oxenes ; and on a new Method of determining the Extinc- 

 tion Angles of these Minerals by Means of Cleavage Pieces. 

 By R. a. Daly 309 



XIII. A Revision of the Atomic Weight of Nickel. Second Paper. — 



The Determination of the Nickel in Nickelons Bromide. By 

 Theodore William Richards and Allerton Seward 

 • CUSHMAN 323 



XIV. A Revision of the Atomic Weight of Cobalt. Second Paper. — 



The Determination of the Cobalt in Cohaltous Bromide. By 

 Theodore William Richards and Gregory Paul 

 Baxter 349 



XV. A Comparative Study of Etch-Figures. The Amphiboles and Py- 

 roxenes. By R. a. Daly 371 



XVI. On a neiv Variety of Hornblende. By R. A. Daly .... 431 



XVII. The Orthojiteran Genus Schistocerca. By Samuel II. Scudder 439 



XVIII. On Hardystonite, a new Calcium-zinc Silicate from Franklin 



Furnace, New Jersey. By John E. Wolff .... 477 



XIX. 1. Eleocharis ovata and its American Allies. 



2. Scirpus Eriophorum and some related Forms. By 1\I. L. 



Fernald 483 



XX. 1. Revision of the Genera Montanoa, Perymeninm, and Zalu- 

 znnia. Bv B. L. Robinson and J. M. Greexman. 



2. Synopsis of the Genus Verbesina, ivith an Analytic Key to the 



Species. By B. L. Robinson and J. jNI. Greenman. 



3. Some new Species, extended Ranges, and newly noted Identities 



among the Mexican Phanerogams. By J. M. Greenman 505 



XXI. Pctrographical Notes on some Rocks from the Fiji Islands. By 



Arthur S. Eakle 579 



XXn. Investigations on Periodicity in the Weather. By H. Helm 



Clayton 597 



