The two small carabids of this genus in Otago and Southland are very similar in form and colour. However, N. procerula is widespread and found in many lowland remnant forest sites whereas N. edax is rare and known only from a single subalpine site. A third, a new species, is also in a lowland site and a fourth, a further new species, is also rare and known from a single alpine locality. To the west in Fiordland lie Neoferonia prolixa and Neoferonia straneoi which is thought to be a species with two names (synonyms).