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OF THE

AMERICAN ACADEMY

OF

ARTS AND SCIENCES.

NEW SERIES,

YOL. V.

CAMBRIDGE AND : METC?LF AND COMPANY, PRINTERS TO THE UNIVERSITY.

1855. MEMOIRS

O? THB

AMERICAN ACADEMY

OF

ARTS AND SCIENCES.

NEW SERIES.

YOL. Y.

CAMBRIDGE AND BOSTON: METCALF AND COMPANY, PRINTERS TO THE UNIVERSITY.

1855. CONTENTS OF PART II.

X. Caroli a Linn? ad Bernardum de Jussieu ineditae, et mutu Bernardi ad Linnae de um Epistolar ; curante Adriano Jussieu..179 some XL The Numerical Relation between the Atomic "Weights, with Thoughts on the Classification of the Chemical Elements. By Josiah P. Cooke, Jr., A.M. 235

XII. A History of the Fishes of Massachusetts. By David Humphreys Storer, M. D., A. A. S. (With Seven Plates.) (Continued.).257 : some XIII. Plantee Novje Thurberian^e The Characters of New Genera and Species a of Plants in Collection made by George Thurber, Esq., of the late Mexican Boundary Commission, chiefly in New Mexico and Sonora. By Asa Gray, M. D.297

XIV. On the Affinities of the Genus VAV^EA, Benth. ; also of RHYTIDANDRA, Asa M. D. . . Gray. By Gray, .329 on XV. On Two New Crystalline Compounds of Zinc and Antimony, and the Cause of the Variation of Composition observed in their Crystals. Bv Josiah P. a ...... Cooke, Jr., A. M. (With Plate.) \ 337

XVI. Discussion of Observations for the Isodynamic, Isogonic, and Isoclinal Curves of on near Terrestrial Magnetism and the Line of the Boundary Survey between the and Mexico, made in 1849, 1850, 1851, and 1852, under the Orders of W. H. Emory, and. combined with Observations at San Francisco (California), and Dollar Point (East Base), and Jupiter (Texas), furnished by a A. D. Bache. (With Map.).372

XVII. Descriptions of New Species of Fossils, from the Cretaceous Formations of Ne braska, with Observations upon Baculites ovatus and B. compressus, and the Progressive Development of the Septa in Baculites, Ammonites, and . . Scaphites. By James Hall and F. B. Meek. (With Eight Plates.) 379

. . Statutes and Standing Votes of the American Academy of Arts and Sciences i Fellows of the American Academy of Arts and Sciences.ix OFFICERSOF THE AMERICANACADEMY,

FOR THE YEAR BEGINNING MAY 29, 1855.

President. JACOB BIGELOW.

Vice-President. DANIEL TREADWELL.

ASA GRAY,.Corresponding Secretary. . . . SAMUEL L. ABBOT, Recording Secretary. EDWARD WIGGLESWORTH, . Treasurer. . NATHANIEL B. SHURTLEFF, Librarian and Cabinet-Keeper.

Standing Committees.

. EBEN N. HORSFORD, DANIEL TREAD WELL, . JOSEPH LOVERING, > Rumford Committee. HENRY L. EUSTIS, . MORRILL WYMAN, s JOSEPH LOVERING, '. LOUIS AGASSIZ, . > Committee of Publication. FRANCIS BOWEN,

AUGUSTUS A. GOULD, . BENJAMIN A. GOULD, > Committee on the Library, . JOSIAH P. COOKE, Jr., . CHARLES JACKSON, Jr., > Auditing Committee. THOMAS T. BOUV?,

Council. Class 1. Class 2. JOSEPH LOVERING, LOUIS AGASSIZ, J. INGERSOLL BOWDITCH, JOHN B. S. JACKSON, BENJAMIN A. GOULD, Jr. .

Class S. JAMES WALKER, JARED SPARKS, NATHAN APPLETON.