iv CONTENTS. 



Paoi 



XII. A '■ <m tin Chief Theorem <>f Lie's Theory of Continu 



Groups. Bi mi I'm \ 1m. mi b Slocdm 287 



XIII. .1 Revision of the Atomic Weight of Iron. Preliminary Paper. 



By THEODOBE W 11 mam RlCHABDfl am> GbEGOKI PAUL 



Baxter ur. l 



XIV. On Certain Colored Substances Derived from Nitro Compounds. 



Third Paper. By C. Losing Jackson am. !•'. II. Gazzolo 261 



XV. The Metamerism of the Hirudinea. By W. E. Castle . . . 283 

 XVI. 1. New Species and Varieties of Mexican I 'Ian Is. l!v J. .M. 



(ikl.l NMAN. 



2. Synopses of the Genera Jaegeria an, l Russelia. By B. L. 



Robinson. 



3. New Dioscoreas from Mexico. By E. B. I'i.ink. 



4. New Phaenogams, chiefly Gamopetalae, from Mexico and 



Central America. By B. L. Robinson 805 



XVII. The Freshwater Tertiary Formations of tin Rocky Mountain 



Region. By W. M. Davis :;;:; 



XVIII. On tin 1 Ihtt rmination of Sulphuric Acid in the Presence of Iron ; 

 a Note on Solid Solutions. By THEODOBE Wii.i.iam 



Ri< hards 876 



XIX. Tht Species of the Orthopleran genus Derotmema. By Samuel 



II. Scuddkk 385 



XX. View of the Carboniferous Fauna of the Narragansctt Basin. 



By Axpheus S. Pa<"kaki> 397 



XXI. Preliminary Diagnoses of New Species of Laboulbeniaceae. — 77. 



By Roland Thazteb 407 



XXII. Historical Notes relating to Musical Pitch in the United States. 



P.y Chables R. Cboss l"'l 



XXIII. The Driving Energy of Physico- Chemical Reaction, and its 



Temperature Coefficient. ByThi >re Wii 1 1 in Rich lbds I6fl 



XXIV. Supplementary Note on the Chief Theorem of Lie's Theory of 



FiniL Continuous Groups. B\ Stephen Elmer Sloccm . 4S1 



