Pisulinella SP.

PISULINELLA? SP. (FIG. 6)

Material studied: Lower Miocene (Burdigalian), France, Landes, Mimbaste; 1 ex. (MNHN-PL 15356). Only one juvenile specimen of this form has been collected from the Lower Miocene (Burdigalian) of Mimbaste (Landes). This outcrop has yielded some elements of hard bottom and cryptic fauna (Neritopsidae, Pickworthiidae) associated with a rich marine littoral sand fauna. The protoconch of Pisulinella ? sp. bears several ribs similar to those observed in the genera Pisulinella and Bourdieria. The teleoconch is sculptured with fine spiral ribs that exclude assignment to B. faviai. P. aucoini differs by the absence of spiral ribs on the teleoconch. I consider that this specimen represents a third undescribed marine neritiliid species, although a full description and clear indication of generic position is postponed until further material becomes available. Placement within the genus Pisulinella is based on the fact that the sculpture comprises only very fine spiral ribs - specimens of B. faviai which are the same size already bear strong spiral cords.