ON PETALIFERA PETALIFERA (RANG, 1828) (GASTROPODA: OPISTHOBRANCHIA): NEW ANATOMICAL AND GEOGRAPHICAL DATA

The anaspidean gastropod Petalifera petalifera (Rang, 1828)is a common species in Mediterranean waters, where it was originallydescribed from Nice, although it has a wider geographical range,living in both East and West Atlantic warm waters. A detailedanatomical description of this species is given, using the scanningelectron microscope to study the radula, jaws and palatal rodsas well as the inner structure of the penial sheath. Examination of the type material of the Red Sea species Aplystellagravien Vayssiè;re, 1906 indicates that it is a synonymof Petalifera petalifera (Rang, 1828). Thus the geographicalrange of the latter is extended to the Gulf of Aden, in theRed Sea. (Received 29 August 1995; accepted 10 November 1995)