10.— Plate III. 



impressed round the upper part, tumidly gibbous 

 round the middle ; columella scarcely twisted. 



Anthony, MS. 



Eab. Southern United States. 



A smooth straightly fusiform shell, of a dull lurid-purple 

 colour throughout. 



Species 21. (Mus. Anthony.) 



Io INERMIS. Io testa obeso-fusiformi, fulvd, intus obscure 

 purpurea fasciatd, anfractibus lavibus, inermibus, su- 



perne concavo-impressis, medio obtuse tumidis; columella 

 arcuato-contortd. 



The unarmed Io. Shell stoutly fusiform, fulvous, ob- 

 scurely purple-banded within, whorls smooth, un- 

 armed, concavely impressed round the upper part, 

 obtusely swollen in the middle ; columella arcuately 

 twisted. 



Anthony, Pro. Acad. Nat. Sci. Philadelphia, 1860, p. 70. 



Hab. Tennessee, United States. 



I quoted this species in Plate I. as a spineless variety 

 of /. spinosa, but it appears to be distinct. 



