IDUO. 



493 



coniplanatus, Soland. 

 confertus, Lea. 

 Congaraeus, Lea. 

 corrugatus, Retz. 

 cultelliformis, Conr. 

 Ouvierianus, Lea. 

 Dariensis, Lea. 

 declivis, Say. 

 depressus, Lam. 

 exolescens, Gould. 

 farnelicus, Gould. 

 fratenius, Lea. 

 fuliginosus, Lea. 

 fulvus, Lea. 

 Geddingsianus, Lea. 

 Gibbesianus, Lea. 

 Griffithianus, Lea. 

 Hopetonensis, Lea. 

 jejunus, Lea. 



limatulus, Conr. 

 litoralis, Drop. 

 lutulentus, Gould. 

 modestus, Ferus. 

 neglectus, Lea. 

 obesus, Lea. 

 occidentalis, Conr. 

 paliatus, Raven. 

 paludicolus, .Gould. 

 Roanokensis. Lea. 

 rufusculus, Lea. 

 sordidus, Lea. 

 subplanus, Conr. 

 symmetricus, Lea. 

 tetralasmus, Say. 

 tortivus, Lea. 

 Tuomeyi, Lea. 

 Watereensis, Lea. 

 Whiteianus, Lea. 



Sub-gen. hyridella, Swainson (Micromya, Agass.). 

 Shell not winged, oval; surface of valves smooth. 



affinis, Lea. 

 altilis, Conr. 

 aincenus, Lea. 

 approximus, Lea. 

 aratus, Lea. 

 australis, Lam. 

 Batavus, Lam. 

 Bengalensis, Lea. 

 Binneyi, Lea. 

 Bonneaudii, Eyd. 

 Brumbyanus, Lea. 

 Bucklyi, Lea. 

 Burroughianus, Lea. 

 buxeus, Lea. 

 caBruleus, Lea. 



VOL. It. 



Caffer, Krauss. 

 caliginosus, Lea. 

 capax, Green. 

 capsseformis, Lea. 

 cariosus, Say. 

 charruanus, D'Orb. 

 Children!, Gray. 

 Claibornensis, Lea. 

 Clarkianus, Lea. 

 concavus, Lea. 

 constrictus, Conr. 

 creperus, Lea. 

 crocatus, Lea. 

 Cumberlandianus, Lea. 

 delodontus, Lam. 



3 s 



