Abstract

A new polyclad species, Tytthosoceros inca is described from Chilean coastal waters. It resembles Pseudoceros luteiis (Plehn, 1898) Hyman 1953 incerta sedis but differs in having ear-like pseudotentacles, a brown marginal band, and dark brown spots on the dorsal surface of the body. Tytthosoceros inca is associated with the colonial ascidians dona intestinalis and Pyura chilensis, living on or near them. This is the first record of the genus from Chilean coastal waters and the second report of the family from cold temperate waters, although this time from the southern hemisphere.