Hemiarthrum setulosum is a species of chiton in the family Hemiarthrumidae, and the only member of the genus Hemiarthrum. It was previously assigned to the family Hanleyidae.Powell A. W. B., New Zealand Mollusca, William Collins Publishers Ltd, Auckland, New Zealand 1979

Hemiarthrum setulosum represent one of the five major clades of chitons that are living. Hemiarthrim setulosum has an incomplete lateral tract in the nerve ring. They are the only known species to have an incomplete one. Sumner‐Rooney, Lauren, and Julia D. Sigwart. "Do chitons have a brain? New evidence for diversity and complexity in the polyplacophoran central nervous system." Journal of morphology 279.7 (2018): 936-949.

Synonym Hemiarthrum hamiltonorum Iredale & Hull, 1932: synonym of Hemiarthrum setulosum P. P. Carpenter [in Dall], 1876 (junior subjective synonym)

Distribution This species occurs off the Kerguelen Islands and Cape Horn.

References

Rochebrune, A.-T., 1889 - Polyplacophores. In Rochebrune, A.T. & Mabille, J., Mission Scientifique du Cap Horn, vol. 6, part. Zoologie, p. 131-143, pl9 Spencer, H.G., Marshall, B.A. & Willan, R.C. (2009). Checklist of New Zealand living Mollusca. Pp 196-219. in: Gordon, D.P. (ed.) New Zealand inventory of biodiversity. Volume one. Kingdom Animalia: Radiata, Lophotrochozoa, Deuterostomia. Canterbury University Press, Christchurch

External links Dall, W. H. (1876). Mollusks. In: J.H. Kidder, Contributions to the natural history of Kerguelen Island, made in connection with the United States "Transit-of-Venus" Expedition, 1874-1875, II. Bulletin of the United States National Museum. 3: pp. 42–48