Curvella  

Pilsbry (1906) descriptions on Curvella – “Shell oblong-conic, perforate or imperforate, thin, translucent, covered with a thin, pale cuticle (as in Opeas); growthlines strongly arcuate. Apical whorl obtuse, rounded and smooth. Aperture ovate, the outer lip acute, arching forward in the middle, retracted at suture and base; columella slightly sinuous or straight, curving into the basal margin. Central tooth of the radula narrow, laterals tricuspid.”

“This genus is separated from Opeas by the forwardly arched outer lip, the shorter, wider contour, and usually smaller number of whorls. The columella is frequently sinuous. In some cases the separation from Opeas seems some what arbitrary, and the boundaries of the two groups in detail are still unsettled. The species were considered Bulimi in the older classifications, but there is no doubt that they are Achatinoid. Reproduction is by globular eggs, small and calcareousshelled, as in the closely related group Opeas.” (Pilsbry, 1906)