84 LIST OF CONTRIBUTORS. 



Lea, Isaac. Continued. 



On the classification of Naiades. P '52, 55 



On the definition of "Species." P '52, 55 



On shells from the drift near Philadelphia. P '52, 106 



■ On supposed imprints of human feet. P '52, 106 



■ Description of a new species of Eschara from the Eocene of 



Alabama. P '52, 109 



Notice of the Mya nodulosa Wood. P '53, 368 



On Castalia sulcata Krauss and other Naiades. P '53, 376 



On Mulleria Fer. P '53, 435 



On reptiles supposed to be from Old Red Sandstone. P 



'53, 435 



— On Pholas dactylus. P '53, 438 



— On Aeostaea guaduasaiia. P '54, 1 



— ■ Rectification of Mr. T. A. Conrad's "Synopsis of the Family 



of Naiades of North America " published in the "Proceedings 

 of the Academy of Natural Sciences of Philadelphia, February, 

 1853." P '54, 236 



— On a tanned skin of the walrus. P '55, 265 



— ■ Description of a new mollusk from the Red Sandstone near 

 Pottsville, Pa. P '55, 340 



— On footprints in the sandstone of Middletown, Connecticut. 



P '55, 409 



— On the New Red Sandstone formation of Pennsylvania and 



on the tooth of a sauroid reptile. P '56, 77 



— Descriptions of a new species of Triquetra Klein (Hyria 

 Lamarck.) P '56, 79 



— Description of a new sub-genus of Naiades. P '56, 79 



— Description of new fresh water shells from California. P 



'56, 80 



— Description of twenty-five new species of exotic Uniones. 

 P '56, 92 



— Description of four new species of exotic Uniones. P '56, 103 



— Description of thirteen new species of exotic Peristomata. 



P '56, 109 



— Description of fifteen new species of exotic Melaniana. P 

 '56, 144 



- — Description of the byssus in the genus Unio. P '56, 213 



— Description of eleven new species of exotic Uniones from 



Georgia. P '56, 262 

 - On Triquetra lanceolata. P '56, 300 



