CONTENTS. 



PART I. NOVEMBER, 1850< 



Art. L— An attempt to classify the Longicorn Coleoptcra of the part of AffieHca Nofth of McxlcO. 



Bj-JohnL. LeConte, M. D.,* . ....... 5 



Art. II."— Descriptions of one new Cretaceous, and seven New Eocene Fossils. By T. A. Conrad, f 89 



Art. III.— Descriptions of some American Annelida abranchia. By Joseph Leidy, M. t)., . -3 



Art. IV. — Descriptions of Owls, preeumed to be new species, in the collection of the Academy of 



Natural Sciences of Philadelphia. By John Cassin, ..... 61 



Art. V. '^Description of a new .species of Mergulus, Ray, from the coast of California. By William 



Gambel, M. D,, ......... fJ5 



Art. VI.— Descriptions of fifteen new species of Crinoidea from the sub-carboniferous limestone of 



Iowa, collected during the U. S. Geological Survey of loWa, Wisconsin, and Minnesota, in 



the years 1848-^. By David D. Owen, M. D., and B. P. Shumard, M. D., . . 67 



Art. VII.— Fossil Footprints of Connecticut River. By James Deane, M. D., . . ?t 



Art, VIII— On the Giant Wolf of North America— 'Lupas gigas. By John K. Townscnd, M. D., 73 



PART II. JANUARY, 1852. 



Art. IX.-^Substance of notes made during a Geological Reconnoissancc in the Auriferous Porphy= 



ry region next the Carribbean Sea, in the province of Veraguas and Isthmus of Panama. 



By Richard C. Taylor, . . . . , .81 



Art. X.— 'The North American Jackal— Canis Frustror. By S. W. Woodhouse, M. D., , 8t 



Art. XI. -^^Descriptions of seven new species of Crinoidea from the sub-carboniferous limestone of 



Iowa and Illinois. By David D. Owen, M. D., and Benjamin P. Shumard, M. D., . 89 



Art. XII. — Descriptions of Owls presumed to be new species, in the collection of the Academy of 



Natural Sciences of Philadelphia. By John Cassin, ..... 95 



Art. XIIL— An attempt to classify the Longicorn Colcopetra of the part of America North of Mexico. 



By John L. Le Conte, M. D.,| ....... 69 



Art. XIV.— Monograph of the Birds composing the genera Hydropsalis, Wagler, and Antrostomus, 



Nuttall. By John Cassin, .....••; 113 



Art. XV. — On the Genus Acosteea of D'Orbigny, a Fresh Water Lamellibranchia. By Isaac Lea, 125 

 Art. XVI. — Description of a new species of the genua Paradisea, Linn., in the collection of the 



Academy of Natural Sciences of Philadelphia. ...... 1.33 



Art. XVII. — Description of a new species cf Crocodile from the Miocene of Virginia. By Joseph 



Leidy, M. D.,l| .......... 135 



* E.xtra copies printed for the Author, March, 1850. 

 t " " " April, 1850. 



♦ " " " October, 1851. 

 I " " " December, 1961. 



