REDESCRIPTION OF TYRINNA-NOBILIS BERGH, 1898 (OPISTHOBRANCHIA, CHROMODORIDIDAE) FROM PATAGONIA, ARGENTINA

The chromodorid nudibranch Tyrinna nobilis, described originally by Be rgh, 1898 from Chile, has been collected on the Atlantic coast of Pata gonia (Argentina). We have made a redescription which includes the pre sence of a vestibular gland, absent in the Bergh's description, and pr ovided information on the biology of the living animals. Tyrinna nobil is was compared with other nominal species assigned to the genera Cadl ina and Tyrinna. Tyrinna pusae Marcus, 1959 was synonymised with T. no bilis, and Cadlina burnayi Ortea, 1988 was included in Tyrinna. The pr esence of a ramifying vestibular gland in T. nobilis, was discussed in relation to phylogeny of the family Chromodorididae.