14 



They may be known by 



Melania having a regular loop-form aperture. 



Anculosa having a roi'nded aperture and a callous columella. 



To having a greater or less elongate channel or spout at the base. 



Lithasia having a callus on the columella above and below, and a notch at 

 the base. 



Schizosloma having a cut in the upper part of the outer lip. 



Strephobasis having a retrorse callus at base and usually a squarish aperture. 



Trypanostoma having an expanded outer lip and an auger-shaped aperture. 



Goniobasis having usually a subrhomboidal aperture, subangular at base and 

 without a channel. 



Am?iicola* having a round mouth and no callus. 



Goniobasis osculata. — Testa, laevi, pupeeformi, subelevata, subcrassa, luteo- 

 fusca, quadrivittata; spirit subelevata; suturis valde et irregulariter impressis ; 

 anfractibus septenis, convexiusculis ; apertura parva, constricts, subelliptica, 

 intus albida et vittata ; labro acuto ; columella alba, inflecta, ad basim contorts 

 et subangulata. 



Sab. — Coosa River, Alabama, b. . ahowalter, M. D. 



Goniobasis Brumbyi. — Testa. lajvi, attenuate, subtenui, cinerea, quadrivit- 

 tata ; spira attenuate, ad apicem carinata ; suturis valde impressis ; anfracti- 

 bus instar octonis, convexiusculis ; apertura parva, subrhomboidea, intus 

 albida et quadrivittata; labro acuto; columella inflecta, ad basim obtuse 

 angulata. 



Hab. — Alabama, Prof. Brumby. 



Goniobasis Grosvenorii. — Testa lajvi, subattenuata, tenui, cornea, fulgida, 

 evittata; spira subattenuata, mucronata, ad apicem carinata; suturis regu- 

 lariter et valde impressis; anfractibus octonis, convexis; apertura parva, sub- 

 rotunda; intus albida; labro acuto, paulisper sinuoso ; columella inflecta, 

 tenui et contorta. 



Hab. — Fox River, Illinois, H. C. Grosvenor; and Quincy, Ohio, J. Clark. 



Goniobasis parva. — Testa lasvi, conica, tenui, cornea, evittata ; spin! sub- 

 elevata, mucronata; suturis impressis ; anfractibus septenis, planulatis : aper- 

 tura parviuscula, intus albida, subrhomboidea ; labro acuto et sinuoso: colu- 

 mella inflecta et paulisper incrassata. 



Hab. — Georgia, Right Rev. Stephen Elliott. 



* Amnicola, although much like Paludina, is more nearly allied to the Mdanider. Tiw 

 operculum is spiral, and therefore very different in this character from Paludina 



