vel vittata vel evittata; spira regulariter elevata; suturis parum impressis; 

 anfractibus instar denis, planulatis ; apertura parviuscula, rhomboidea, intus 

 albida; labro acuto, valde sinuoso; columella inferne incrassata et valde 

 contorta. 



Bab. — Tuscumbia, Ala., L. B. Thorton, Esq. and Rev. G. White. Chatta- 

 nooga, Tenn., J. Clark. 



Tktpanostoma Troostii. — Testa carinata, conoidea, valde inflata, vel luteo- 

 cornea vel viridescente, vel vittata vel evittata ; spira. elevata ; suturis valde et 

 irregulariter impressis ; anfractibus instar novenis, subimpressis, interdum 

 canaliculatis ; apertura grandi, rhomboidea, intus albida, interdum vittata ; 

 labro acuto, sinuoso ; columella inferne incrassata et valde contorta. 



Bab. — Tennessee, Prof. 6. Troost. Florence, Ala., Rev. G. White. Ooste- 

 naula River, Ga., Bishop Elliott ; and Fox River, near New Harmony, Indiana. 

 J. Sampson. 



Tbypanostoma kcubvum. — Testa carinata, conoidea, subtenui, cornea ; spira. 

 subelevata ; suturis regulariter impressis ; anfractibus octonis, planulatis, in- 

 ferne obsolete striatis ; apertura parviuscula, rhomboidea, intus albida ; labro 

 acuto, sigmoideo ; columella valde contorta. 



Bab.— Florence, Ala., Rev. G. White. 



Tbtpanostoma Postellii. — Testa carinata, pyramidata, subcrassa, cornea ; 

 spira regulariter conica; suturis valde impressis; anfractibus octonis, vel 

 planulatis vel impressis, ultimo parviusculo ; apertura parvissima, rhomboidea, 

 intu3 albida ; labro acuto, valde sinuoso ; columella inferne incrassata et valde 

 contorta. 



Bab. — Tennessee River, J. Postell. North Alabama, Prof. Tuomey. 



Tbypakostoma Tuomeyi. — Testa carinata, crassiuscula, elevato-conica, tene- 

 broao-fusca ; spira elevato-conica ; suturis vix impressis ; anfractibus instar 

 denis, planulatis, inferne obsolete striatis ; apertura parva, rhomboidea, intus 

 tenebrosa ; labro acuto, sinuoso ; columella paulisper incrassata, et valde 

 contorta. 



Bab.— North Ala., Prof. Tuomey. Florence, Ala., Rev. G. White. 



Tbypanostoma Flobencense. — Testa subcarinata, turrita, subcrassa, tene- 

 broso-fusca vel luteo-cornea, obsolete vittata vel evittata ; spira valde elevata ; 

 suturis leviter impressis ; anfractibus instar undenis, paulisper convexis ; aper- 

 tura parvinscHla, rhomboidea, intus caeruleo-alba ; labro acuto, sinuoso ; colu- 

 mella albida et valde contorta. 



Bab.— Florence, Ala., Dr. Spillman. Tuscumbia, L. B. Thornton, Esq. 



