Newcomb's snail, is recognized as a valid species. Bengt Hubendick (1952) did not believe the distinctive shell form (described below) and reduced structures of the nervous system of Newcomb's snail warranted a genus (second species of the genus "Erinna" is considered extinct). In fact, Hubendick included all Hawaiian lymnaeids in the genus "Lymnaea". Joseph Paul Eldred Morrison (1968) contradicted Hubendick and argued the distinctive shell characters of Newcomb's snail supported the generic name "Erinna". John B. Burch (1968), Charlotte M. Patterson and Burch (1978), Dwight Willard Taylor (1988), and Robert H. Cowie et al. (1995) all followed Morrison and referred to Newcomb's snail as "Erinna newcombi", which is the currently accepted scientific name.