The genus Pupoides differs from the Family Pupilla by several different adaptations in the characteristics of its shell.  The shell has a tapering spire and longer whorls, which are not as tightly coiled. There is also an absence of any furrow or crest behind the lip of the shell, and the opening of the shell is somewhat longer than seen in Pupilla(Pilsbury 1948).Some variations of shell size can be found among different distributions of the snail depending on where they are located. Shells from the northeast are somewhat thicker, shells from some Arizona colonies are slightly smaller and  more delicate, and the most slender examples of the species usually come from the gulf states(Pilsbury 1948). For reproductive adaptations, see Reproduction.