Dorymenia troncosoi nov. (Mollusca Solenogastres : Proneomeniidae), a new species from the South Shetland Islands (Antarctica)

During the Spanish oceanographic expedition BENTART '95, carried out in Ant arctic waters off Livingston Island (South Shetland Islands), five small sp ecimens of a new species of Solenogastres-Cavibelonia, Dorymenia troncosoi sp. nov., were collected at a depth of 65-240 m on a silt bottom. The speci es is characterized by the presence of a pallial cavity with four pouches ( a dorsal, two lateral and a ventral pouch), seminal receptacles that open i nto the spawning ducts through a short duct, radula having 9-11 teeth per r ow (1 central and 4-5 lateral, all the same size), the end, of the copulato ry spicules having a cross-section in the shape of a four-pointed star, and abdominal spicules present. These characteristics separate this species fr om other species of the genus, particularly from Dorymenia profunda, which is the most similar.