LIST OF CONTRIBUTORS. Ul 



Hora, Geo. H., M. D. Monograph of the species of Trogosita, inhabiting 



the United States 32 



Lea, Isaac. Description of ten new species of Unionida? of the United 



States 168 



Description of anew Genus (Trypanostoma) of the Family Melanida?, and 



of forty-five new species 169 



Description of two new species of Exotic Uniones and one Monocondylcea 176 

 Description of a new Genus (Gouiobasis) of the Family Melanidae and 



eighty-two new species 262 



Description of eleven new species of Melanidae of the United States 272 



Le Conte, John L., M. D. Note on the Classification of Cerambycidse, with 



descriptions of new species 38 



Synopsis of the Mordellidae of the United States 43 



Notes on the species of Calosoma inhabiting America, north of Mexico... 521 



Synopsis of the species of Colymbetes, inhabiting America north of Mexico 521 



Note on the species of Brachinus inhabiting the United States 523 



Lewis, James, M. D. Remarks on some species of Paludina. Amnicola. 



Valvata and Melania 587 



Meehan, Thos. On the Uniformity of Relative Characters between Allied 



Species of European and American Trees 10 



Meek, F. B. Descriptions of new Cretaceous Fossils from Nebraska Terri- 

 tory. ByF. B. MeekandF. V. Hayden 21 



Prime, Temple. Monograph of the Species of Sphasrium of North and 



South America 28 



Slack, J. H. ? M. D. Monograph of the Prehensile-tailed Quadrumana 507 



Stimpson, Wm. Description of a new Cardium from the Pleistocene of 



Hudson's Bay 58 



Oa an oceanic Isopod, found near the south-eastern shores of Massachu- 

 setts 133 



Tryoc, Geo. W., Jr. On the Classification and Synonymy of the recent spe- 

 cies of Pholadidaj 191 



Description of a new Genus and Species of Pholadid* 449 



Notes on American Ffesh Water Shells, with descriptions of two new 



species - 451 



Monograph of the Family Teredidae 453 



Walsh, Benj. D., M. A. List of the Pseudoneuroptera of Illinois, contained 

 in the Cabinet of the writer, with descriptions of over forty new 

 species - 361 



Warner, John, A. M. Contributions to Organic Morphology : Containing 

 the mathematical imitation of the egg of Planorbis Corneus and of 

 Epiornis, &c 525 



Winchell. Alex. Description of Fossils from the Marshall and Huron 



Groups of Michigan 405 



