Smith, 1881) are very similar in morphology, and were collected only 400 km (250 mi) apart; as long ago as 1908 this led to the recognition that they were probably the same species.

Despite this, they continued to be treated as two separate species until 2011, when Nakano et al. researched the genus and brought them into synonymy.

I. emarginuloides was described before I. coppingeri,[2] so by the rules of zoological nomenclature, the earlier name took priority.

[4] Although limpets in the family Lepetidae are commonly known as "blind limpets", both this species and the closely related Iothia fulva have small, black-pigmented eyes, situated close to the base of the tentacles.

[5] Its distribution is probably circum-Antarctic, with its known range extending from the Kerguelen Islands to the Strait of Magellan area.