iv CONTENTS. 



Page. 



XII. Description of an American Spider, constituting a new sub- 

 genus, of the tribe Insequitelae of Latreille ; by Prof N. 



M. Hentz, 116 



XIII. Contributions to Electricity and Magnetism— No. IV. On 

 Electro-Dynamic Induction; by Prof Joseph Henry, 

 LL.D., .117 



XIV. A Brief, Preliminary Account of the Hessian Fly and its 

 Parasites ; by Edward C. Herrick, .... 153 



XV. Proceedings of Learned Societies : 



I. Association of American Geologists, . . . • 158 



II. Boston Society of Natural History, . . . 189 



Miscellanies. — Proceedings of the Geological Society, 190. — The 

 former existence of Glaciers in Scotland, 191. — Red Color of 

 the Salt Marshes of the Mediterranean : New Observations on 

 the Infusoria of Rock Salt : Ornithological Gallery of the Brit- 

 ish Museum, 193. — Prof Agassiz and his Works, 194. — Sketch 

 of the Geology of North America, 195. — Outlines of Anat- 

 omy and Physiology, translated from the French of H. Milne 

 Edwards, 199. — Volcanic Phenomena in Hawaii : Manilla 

 Hemp, 200. — National Institution at Washington for the pro- 

 motion of Science, 203. — Fossil Turtle : Fossil Saurians : Mi- 

 croscopical Observations and Microscopes, 205. — Geological 

 Drawings, 206. — Glaciers, Moraines, &c. : British Associa- 

 tion — Mr. Murchison — His Journey to the Ural mountains — 

 Opinions, fee, 207. — Dr. Brown of Edinburgh on the Produc- 

 tion of Silicon from Paracyanogen, 208. — Artesian Boring 

 at Paris, 209. — The Theory of Horticulture : Correspond- 

 ing Magnetic Observations, 210. — Fossil Foraminifera in the 

 Green Sand of New Jersey, 213. — Discovery in Virginia of 

 the regular Mineral Salt Formation, 214. — Proceedings of the 

 Academy of Natural Sciences of Philadelphia, 215. — A Trea- 

 tise on the Theory and Practice of Landscape Gardening, 

 adapted to North America, 216. 



NUMBER II. 



Art. I. Notice of the late Sheldon Clark, Esq. of Oxford, Connec- 

 ticut ; by Prof. Silliman, 217 



II. First Anniversary Address before the Association of Amer- 

 ican Geologists, at their second annual meeting in Phila- 



