SECTION B.] NORTH AMERICAN CONCIIOLOGY. 



557 



[Proceedings Academy of Natural Sc] 

 May, 1858. 

 Page. 



118 Lea. — Description of four new Fresh Water Mollusca from the 

 Isthmus of Darien and Honduras : by Isaac Lea. 



US Unio Caldwellii Lea. 

 118 Goascoranensis Lea. 



118 Anodonta luteola Lea. 



118 Melania planensis Lea. 



Isthmus of Darien. 

 Kiv. Goascoran, Honduras. 

 Isthmus of Darien. 

 Plan, &c, Honduras. 



May, 1S.39. 

 151 Lea. — Descriptions of twenty-one new species of Exotic Unionidse : 

 by Isaac Lea. 



151 Unio Sikkimensis Lea. 



151 diminutis Lea. 



152 plicatulus Lea. 



152 navigioliformis Lea. 



152 fluctiger Lea. 



152 mutabilis L<a. 



152 Thwaitsii Lea. 



152 melleus Lea. 



152 Dysoni Lea. 



152 Demararaensis Lea. 



152 Mauritianus Ze«. 



153 vittatus Lea. 



153 Shanghaiensis Lea. 



153 Layardii L^ea. 



153 Japanensis Lea. 



153 Sumatrensis Lea. 



153 Rowellii Zen. 



153 Wilsoni Lea. 



154 Anodonta Dahomeyensis Lea. 

 154 Senegalensis Lea. 



Sikkim, India. 

 East Africa. 

 Borneo. 



Australia, &c. 

 Ceylon. 



Honduras. 



Demarara. 



Mauritius. 



Australia. 



Shanghai. 



Ceylon. 



Japan. 



Sumatra. 



Chagres riv., N. Granada. 



Isaac's Plain, N. S. W. 



Dahomey. 



Senegal. 



July, 1859. 

 1S7 Lea. — Descriptions of four new species of Exotic Unionida? : by 

 Isaac Lea. 



187 Unio bulloides Lea. 



1S7 Monochondylaea planulata Lea. 



187 rhomboidea Lea. 



1S7 Unio rudus Ze«. 



R. de la Plata. 



Java. 



Euphrates, near Bagdad. 



R. de la Plata. 



Oct. 1S39. 



2S1 Lea. — Description of a new species of Unio from the Isthmus of 

 Darien : by Isaac Lea. 



281 Unio Averyi Lea. Isthmus of Darien. 



