196 AMERICAN JOURNAL 



sides are bounded by straight lines. A difference also exists in 

 the color. In the former the surface is covered by three reddish 

 bands and three light ones, besides a light color on the angle. 

 Over the darker bands are still darker, irregularly elongated, 

 sharply defined patches, while on the lighter bands are smaller, 

 but equally dark spots. In our species there is but a single 

 light band on the middle, or rather a continuation of light, ir- 

 regular cloudings on a yellowish ground, and a similar light 

 coloration on the angle, and near the angle a few small dark 

 spots, shaded into the general ground color of the shell. In the 

 height and concave outline of the spire, the two species are 

 about alike. 



