Anillinus alleni Sokolov and Carlton, new species, is described from the Ozark Mountain Interior Highlands (type locality: Blanchard Springs Recreation Area, Stone County, Arkansas, USA) based on four specimens collected using soil washing followed by Berlese extraction. The species is unique among anilline carabids in possessing extremely large, spinous projections on the male metafemora. It represents the second known anilline species occurring in the Ozark Highlands, both of which were collected using soil-washing techniques. Similarities with other species of Anillinus Casey are discussed, and ideas are presented about the potential adaptive significance of elements of external morphology in relation to subterranean habitats.