On my request Mr H. DE SOUZA LOPES of the Instituto ’Oswaldo Cruz’, Rio de Janeiro, sent me a collection of chitons, preserved in alcohol, which he collected in 1952 in the Estado Rio de Janeiro, Brazil. Among them were two specimens of a Chaetopleura which at first sight reminded me of Ch. fulva (Wood, 1815) from the Atlantic coasts of Spain and Portugal. A closer examination and accurate comparison with Spanish examples of Ch. fulva convinced me of the identity of the Brazilian specimens and the European ones. At the same time I had the opportunity to study a lot of 7 Chaetopleura collected by Mr J. H. JURRIAANSE at Bahia Blanca (Argentina), on June 19th. 1923, which were among the unnamed chitons in the collection of the Rijksmuseum van Natuurlijke Historie, at Leiden. These also showed a close resemblance to Ch. fulva, though I observed some slight differences with the Spanish and Brazilian specimens. They might be called Ch. fulva (Wood) var. tehuelcha (d’Orbigny) for reasons to be set forth in the conclusive part of the present paper.