Four new species of Chaetodermatidae (Mollusca, Caudofoveata) from bathyal bottoms of the NW Iberian Peninsula

Caudofoveata is a class of vermiform molluscs with bilateral symmetry and circular transverse section. There are at least 135 described species of Caudofoveata. Fourteen species have been reported from the coast of the Iberian Peninsula, four of which belong to the family Chaetodermatidae. Of these four species, three are endemic to the Mediterranean Sea and one to the NW Iberian Peninsula. The Chaetodermatidae specimens studied were collected off the NW Iberian Peninsula during several expeditions. Four new species of Caudofoveata are described from the NW Iberian Peninsula. They belong to the family Chaetodermatidae, one of them to the genus Chaetoderma and three to Falcidens. Chaetoderma galiciense sp. nov. has a body divided in 5 regions: anterior, neck, trunk, tail and tassel, each region is covered by typical sclerites. Falcidens urgorrii sp. nov. has a narrow body divided in four regions: anterior, neck, trunk and tassel, each region covered by typical sclerites, and a radula bears a pair of teeth and two pairs of lateral supports. Falcidens garcialvarezi sp. nov. has a body with four regions, each body region covered by characteristic sclerites. The radula bears a pair of falciform teeth, a long and narrow radular cone, a triangular central plate and a pair of lateral supports. Falcidens valdubrensis sp. nov. has a short body divided in four regions, each of which covered by characteristic sclerites; the radula bears two falciform teeth.The four new species described herein increase the number of known described species of Caudofoveata to 138. Thus, the Iberian Peninsula becomes one of the best known areas in the world. Also, the first species of the genus Chaetoderma from the Iberian Peninsula is described. This paper is registered in Zoobank under: http://zoobank.org/urn:lsid:zoobank.org:pub:628A29EE-B45D-4D1A-8955-F84FEDAD9013.