CONTENTS. 



PART III. AUGUST, 1849. 



Art. XIV. — Monograph of Fossil Squalidse of the United States. By Robert W. Gibbes, 



M. D., of South Carolina, Correspondent of the Academy of Natural Sciences of 



Philadelphia, &c., 191 



Art. XV. — Descriptions of new Fossil and Recent Shells of the United States. By T. A. 



Conrad, - 207 



Art. XVI. — Notes on Shells, with Descriptions of new Genera and Species. By T. A. 



Conrad, 211 



Art. XVtI. — Remarks on the Birds of Upper California, with descriptions of new species. 



By William Gambel, M. D., ' - - - - 215 



Art. XVIII. — Additional Observations on a new living species of Hippopotamus. By Samuel 



George Morton, M. D., Penn. & Edinb., 231 



Art. XIX. — Descriptions of new species of Birds of the genera Vidua, Cuvier, Eupledes, 



Swainson, and Pyrenestes, Swainson, specimens of which are in the collection of the 



Academy of Natural Sciences of Philadelphia. By John Cassin, - - - . 241 

 Art. XX. — Cryptocephalinaram Boreali-americss diagnoses cum speciebus novis musei 



lecontiani. Auctore S. S. Haldeman. .---.--- 245 



Art. XXI. — Observations on the Reproductive Organs, and on the Foetus of the Delphinus 



Nesarnak. By Charles D. Meigs, M. D., - - - - . - - - 267 



PART IV. JANUARY, 1850. 



Art. XXII. — Descriptions of New Fresh W^ater and Marine Shells. By T. A. Conrad, - 275 

 Art. XXIII. — Revision of the North American Tailed-Batrachia, with descriptions of new 



genera and species. By Spencer F. Baird, Carlisle, Pennsylvania, ... 281 



Art. XXIV. — Descriptions of new species of the Genera Micrastur, G. R. Gray, Tanagra, 



Linn., and Sycobius, Vieill. By John Cassin, 295 



Art. XXV, — New species of Myliobates from the Eocene of South Carolina, with other 



genera not heretofore observed in the United States. By Robert W. Gibbes, M. D., 



Correspondent of the Academy of Natural Sciences of Philadelphia, &c., - - 299 



Art. XXVI. — Descriptions of two species of Distoma, with the partial history of one of them. 



By Joseph Leidy, M. D., - - - , - 301 



Art. XXVII. — An attempt to classify the Longicorn Coleoptera of the part of America north 



of Mexico. By John L. Le Conte, M. D., 311 



