Type Status:
syntype of Helix alta. Pease, 1868. American Journal of Conchology 4 (3): 153, pl. 12, fig. 1 | syntype of Trochomorpha alta. Pease, 1871. Proceedings of the Zoological Society of London 1871: 474, not figured | holotype of Helix alta. H. B. Baker, 1963.