UNIO. 



tfj 







^ 



t/.' 

 



fc 



OVAL. 



t/m'o orientals. Bourrj. 



*regularis. iea. Chenu. 

 *Paraguayensis. Lea. 



Swinhoei. //. Adams. Reeve. 

 *amcenus. Lea. Chenu. 

 *Sapotalensis. Lea. Chenu. 

 *0regonensis. Lea. 

 *Medellinus. 1 Lea. Chenu. Han. 

 *notatus. Lea. Chenu. Han. 

 *micans. Lea. 

 *perlucens. Lea. 

 *subangulatus. Lea. 

 *sparus. Lea. 

 *Veracruzensis. Lea. 

 *scitulus. Lea. 

 *Goascoranensis. Lea. 

 *gracilior. Lea. 

 *obfuscus. Lea. 

 *rutilans. Lea. 

 *subellipsis. Lea. 

 *datus. Lea. 



OVAL. 



Aucklandicus. Gray. 

 *dispar. Lea. 

 *concestator. Lea. 

 *lienosus.* Con. Kiist. Han. 

 *calliginosus. Lea. 

 *firmus. Lea. 



*Nashvillensis.* Lea. Han. 

 *contiguus. Lea. 

 *umbrans. Lea. 

 *intercedens. Lea. 

 *fallax. Lea. 

 *obscurus. Lea,. 

 *genuinus. Lea. 



*Zieglerianus. Lea. Chenu. Han. 

 *proximus. Lea. 

 *nitens. Lea, 

 *Copei. Lea. 

 *Pjbasii. Lea. 

 *proprius. Lea. 

 *tenebricns. Lea. 

 *Prattii. Lea. 



1 Mr. Say's purpuriatus and this may be the same. I have never seen his specimens, and there is no 

 figure. The description is in the Disseminator, Jan. 1, 1831. 



2 Mr. Conrad, in his Monograph of Unii>i<!n\ p. 61, considers Nafhrillfiiti.*-, Lea, to be the same 

 with Zi'enosws, Con.; but the former shell is certainly not the species figured by him pi. 34, f. 2. 



12 



