104 OBSERVATIONS ON NAIADES, 



CARocoLiiA Spinosa. Plate XV. fig. 35, a, b, c. 



Testd lenticulari, tenui, pellucidd, imperforatd; carina acuta et spinis minutis mu- 

 nita; anfractibus sex; spira fere plana; apertura angustissima; columella den- 

 tem unicum longum et laminatum habente; labro enormiter crasso et prope finem 

 superiorem angulato. 



Shell lenticular, thin, diaphanous, imperforate ; carina acute and armed with 

 minute spines ; whirls six ; spire nearly planular ; aperture linear, being guarded by 

 a long tooth on the columella; outer lip irregularly thick, angulated near the supe- 

 rior termination. 



Hab. Alabama near Clairborne, Judge Tait. 



My Cabinet. 



Cabinet of the Academy of Natural Sciences. 



Diani. eleven-tvs'entieths, Length four-twentieths of an inch. 



Remarks. — For this beautiful and highly interesting species I am 

 indebted to the kindness of Judge Tait. Its peculiar delicate spines 

 distinguished it from all described species. These, however, when the 

 specimens are not perfect, are entirely obliterated. In the construction 

 of the aperture it is unlike every Carocolla I have seen, bearing much 

 resemblance in this region to the Helix hirsuta (Say). 



Valvata Arenifera. Plate XV. fig. 36, a, b. 



Testa orbicidatd, convexd; anfractibus tr^bus, qui arenis agglutinatis operiuntur; 

 uinbilico lato; spira obtusd. 



Shell orbicular, convex ; whirls three, covered by the agglutinations of sand ; um- 

 bilicus wide ; spire obtuse. 



Hab. Cumberland river near Nashville, W. Cooper. 



My Cabinet. 

 Cabinet of W. Cooper. 



