DESCRIPTION OF A NEW SPECIES IN THE GENUS TAMBJA BURN, 1962 (GASTROPODA, NUDIBRANCHIA, POLYCERATIDAE) FROM SOUTHERN SPAIN

A new species of Tambja is described from the western Mediterranean on the coast of southern Spain. The external and internal features of th is species are compared with those of the known Atlantic species of th e genus. Tambja marbellensis sp. nov. varies in color between dark blu e, almost black and dark greenish blue. It has a yellow band on the ed ge of the notum and the foot, and other bands of the same color and di ffering in length,on the notum, flanks, and tail. The radula is typica l of the genus Tambja, with the inner lateral tooth having a conspicuo us denticle on the inner edge of the primary cusp. The second inner la teral tooth also has a small cusp. The reproductive system has a diffe rentiated prostate from the deferent duct, and the bursa copulatrix an d the seminal receptacle are similar in size.