178 HELICID^. 



flattened towards the plane of the base ; hp -nhite, 

 reflected, with a slightly prominent callus, or obtuse 

 tooth, on the inner edge near the base ; umbilicus rather 

 large and profound, exhibiting all the volutions to the 

 apex ; base convex, with the striae converguig into the 

 umbilicus. 



Greatest transverse diameter one inch and one-eighth. 



Geographical Distribution. Inhabits the banks 

 of the Ohio, Mississippi, and Missouri Rivers ; has been 

 observed on the latter as high as Council Bluffs. Found 

 also in the western parts of New .York, Pennsylvania, 

 and Virginia, and in Tennessee. 



The most eastern locality which I have heard of, is 

 near the mouth of the Juniata River in Pennsylvania, 

 where it was noticed by Dr. Griffith. 



Remarks. This is one of our most remarkable shells, 

 by reason of its reddish-brown bands and lines. There 

 is usually one band, on the upper side of each whorl, 

 wholly visible on the body-whorl, and partially concealed 

 on the spire, while on the lower part of the shell there 

 are numerous fuscous lines. In some instances the 

 broad band is deficient ; in others, the lines, and occa- 

 sionally the rufous coloring, extend over the whole shell, 

 leavmg only one or two lighter bands. Specimens are 

 not uncommon of a uniform, pale horn-color, without 

 bands or lines. The superior and inferior extremities 

 of the lip approach each other at their junction with the 

 body-whorl, leaving only a small space of the whorl 



