+s 
Viii CONTENTS. ‘eA 
445.—Medals of Creation: On the Cereus Greggii, by Dr. Excenmann, 446. 4 
—On the Oscillations of Suspension Bridges, by J. H. Réurs, Esq., A.M.: — 
Siberian Exploring Expedition: Rain in the Khassya Hills, 447.— Obituary.— 
John Pitkin Norton, 448.—Charles Athanasius Baron de Walckenaer, 449. ip 
Bibliography.—Address at the Anniversary Meeting of the Royal Geographical _ 
Society, May 24, 1852, by Sir R. I. Morcuison, 450.—On a Fossil Saurian of _ 
the New Red Sandstone Formation of Pennsylvania, and on New Fossil Mol- 
luses in the Carboniferous Slates of the Wilkesbarre Coal Formation, by Isaac 
Lea: On the Fossil Footmarks of Red Sandstone of Pottsville; by Isaac 
Lea, 451.—Catalogue of Shells collected at Panama, with Notes on their — 
_ Synonymy, Station and Geographical Distribution, by C. B. Avams: Proceed- _ 
ings of the American Association for the Advancement of Science, Albany a 
_. -‘Meeting, August, 1851: Elements of Natural Philosophy, by Prof. W. H.C. 
fe Barriertr, LL.D.; 452.—A Descriptive Treatise upon the Sun, Moon and 
_ Planets, including the Solar System, by J. Russet H1np: A Treatise of Ana-— 
Anniversary Meeting of the Geological Society of London, Feb. 20, 1852, b 
Ws. Horxtns, Esq., 453.—The Mastodon Giganteus of North Am 
? 
Surrarp, M.D.: Observations on the Genus Unio, with Descriptions of New 
Species in the families Unionide, Colimacea, and Melaniana, 
455 
ERRATA. 
P. 302, 15th line from top, for 6-articulatum, read 1-6-articulatum. 
P. 305, last line, for 92, read 192. 
P. 306, 5 lines from bottom, for lii, read viii, 
307, 14th line from top, after thoracis insert femine. 
308, 25th line from bottom, for sex, read Imi 2Qdique. 
P.315, 9th line from top, for nudo, read nullo, 
