342 HELICID^E. 



GEOGRAPHICAL DISTRIBUTION. Mr. Say found it 

 abundant on the banks of St. John's River, East Florida, 

 and under the ruins of Fort Picolata. It occurs also 

 near Baltimore and Charleston, S. C., and was brought 

 from the Island of St. Croix, by Dr. Griffith. Mr. Bart- 

 lett found it at Key West and in Arkansas. 



REMARKS. Mr. Say noticed the resemblance between 

 this species and P. corticaria ; future observations will, 

 I believe, prove them to be identical. That the two 

 quoted above as synonymous are so, is fully shown by 

 the comparison of numerous specimens. The length of 

 the spiral cylinder varies considerably. The characters 

 of the aperture are constant ; but the teeth, except those 

 on the transverse margin and at the extremity of the axis, 

 are frecjuently wanting ; its outline is well rounded, and 

 the lip broadly expanded. There is often an abrupt 

 curve of the outer lip between the tooth of that side and 

 its junction with the body whorl. The upper boundary 

 of the aperture is distinctly marked by the body whorl, 

 which makes a horizontal truncature of the superior part 

 of the oval. The teeth, except the two constant ones, 

 are deeply seated in the throat, and cannot always be 

 seen without considerable attention. 



