CONTENTS. 



Page 

 Art. XXVI. — Description of a new Species of Aruchnides^ of 



the Genus Epeira, of M. JValckenaer. By C.Fautbier 224 

 AiiT. XXVII. — On a Quadruped belonging to the Order 



Rodentia. By Thomas Say 227 



Art. XXVIII. — Note on the supposed Identity of the genus 



Isodon of Say, with Capromys. By Thomas Bell, 



Esq. F.L.S 230 



Art. XXIX. — Memoir upon a new genus of Fossil Poly- 



paria. By M. Le Saw age 231 



Art. XXX. — Memoir on an American But, a New Species 



belonging to the genus Nyclinomus. By M. Isidore 



O'eoffroy Saikt-Hilaire 233 



Art. XXXI. — A Revision of the Family Equidce. By Mr. 



John Edward Gray, M.G.S 241 



Art. XXXII. — Descriptions of three new Species of Leth- 



rus. By Professor Fischer 249 



Art. XXXIII. — A Description of Two new species of Ileli- 



cincE, and Explanation of the Figures to the Monograph. 



By Mr. John Edward Gray, M.G.S 250 



Art. XXXIV. — Description of a remarkable Fossil, found 



in Coal Shale : with Observations. By J. D. C. 



SowEUBY, Esq. F.L.S. 252 



Art. XXXV. — On the Structure of Melania Setosa. By 



Mr. John Edward Gray, M.G.S 253 



Art. XXXVI. — Abstract of a Monograph on a new Genus 



of Gasleropodous MoUusca, named Scissurella ; by M. 



Alcide Dessalines D'Orbigny. With Notes by 



G. B. SowERBY, F.L.S 255 



Art. XXXVII. — Mulleria, a new Genus of Fresh-water 



Bivalves, of the Family of Ostreacece, established by 



M. Le Baron D'Audebard de Ferussac 258 



Art. XXXVIII. — Analytical Notices of Books : — 



Monographia Tenthredinetarum 259 



Annales des Sciences Naturelles 264 



Curtis'' s British Entomology 265 



SoKciby's Genera of Recent and Fossil Shells 266 



