A NEW METHOD OF ANALYSIS OF THE PERIOSTRACUM IN PALLETS OF BANKIA GRAY, 1842 (BIVALVIA: TEREDINIDAE)

The wood-boring family Teredinidae (Bivalvia) comprises 15 genera and 71 species.1,2,3 The identification of species is mainly based on the pallets, structures which are exclusive to this family.1,2,3 Each pallet is made up of a stalk and a blade, which is particulary elaborate in the genus Bankia Gray, 1842. In this genus, many cones form the blade and each cone is com-posed of a calcareous portion, covered by the periostracum that can expand laterally to form awns. The free border of the peri-ostracum may be smooth or serrate. The presence or absence of awns, the characteristics of the periostracal free border and the shape of the calcareous portion of the cones have been considered of great value in the identification of species.1,2,3 The pallets may be intensely affected by ecological conditions or by bad preservation of specimens in collections.1,4 In such situations, modifications of the calcareous portion of the cone