Hemiarthrum

Hemiarthrum setulosum is a species of chiton in the family Hemiarthrumidae,^[1] and the only member of the genus Hemiarthrum. It was previously assigned to the family Hanleyidae.^[2]

Hemiarthrum
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Polyplacophora
Order:	Chitonida
Family:	Hemiarthrumidae
Genus:	Hemiarthrum Carpenter in Dall, 1876
Species:	H. setulosum
Binomial name
Hemiarthrum setulosum Carpenter in Dall, 1876
Synonyms
Acanthochiton couthouyi Rochebrune, 1889 (junior subjective synonym) Acanthochiton stygma Rochebrune, 1889 (uncertain synonym) Chiton castaneus A. Gould, 1852 (invalid: junior primary homonym of Chiton castaneus W. Wood, 1815) Hemiarthrum hamiltonorum Iredale & Hull, 1932 Hemiarthrum setulosum Powell, 1957

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. ^[3]

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.