THE NAUTILUS. 53 



Lampsilis apicinus Lea. Tombigbee river, Columbus, Miss. 



Lampsilis trabalis Conrad. Tennessee river. One specimen. 



Lampsilis parvus Barnes. Tombigbee river, Columbus, Miaa. 



Lampsilis cromwellii Lea. Yalabusha river, Grenada, Miss. 



Lampsilis alatus Say. Tombigbee and Tennessee rivers. 



Lampsilis purpuratus Lamarck. Tallahatchie, Yallabusha and 

 Big Black rivers. 



Lampsilis gracilis Barnes. All the rivers visited. 



Lampsilis leptodon Rafinesque. Tennessee river. Two poor 

 specimens. 



Lampsilis claibornensis Lea. Floating creek, Columbus, Miss. 

 Medionidus acutissimus Lea. Tombigbee river and Floating 

 creek, Columbus, Miss. 



Medionidus subtentus Say. Tennessee river, Florence, Ala. 



Obovaria retusa Lamarck. Tennessee river, Florence, Ala. 



Obovaria tinkeri Wright. Yalabusha river, Grenada, Miss. 



Obovaria unicolor Lea. Tallahatchie, Yallabusha, Big Black and 

 Tombigbee rivers, very plenty in the last stream at Columbus, Miss. 



Obovaria ellipsis Lea. Tennessee river, Florence, Ala. 



Obovaria castanea Lea. Tallahatchie, Yalabusha, Big Black and 

 Tombigbee rivers. 



Plagiola securis Lea. Tombigbee and Tennessee rivers. 



Plagiola clegans Lea. Tennessee river, Florence, Ala. 



Plagiola donaciformis Lea. Tallahatchie, Yalabusha, Big Black, 

 Tombigbee and Tennessee rivers. 



Tritogonia tuberculata Barnes. Tallahatchie, Yalabusha, Big 

 Black and Tombigbee rivers. In the Black a few specimens were 

 found with purple nacre. 



Cyprogena irrorata Lea. Tennessee river, Florence, Ala. 



Obliquaria reflexa Rafinesque. Tombigbee and Tennessee rivers. 



Ptchobranchus phaseolus Hildreth. Tennessee river, Florence, Ala. 



Dromus dromus Lea. Tennessee river, Florence, Ala. 



Strophitus spillmanii Lea. Yalabusha river, Grenada, Miss. 



Strophitus tombigbeensis Lea. Tombigbee river, Columbus, Miss. 



Strophitus elliotii Lea. Tallahatchie river, Abbeville, Miss. 



Strophitus schafferianus Lea. Tennessee river, Florence, Ala. 



Anodonta grandis Say. Tallahatchie and Yalabusha rivers. 



Arcidens confragosus Say. Yalabusha, Big Black and Tombigbee 

 rivers. 



