Notes on the Fauna of the Chipola Formation- VIII on the Presence of Arcopagia (Johnsonella) Fausta (Pulteney) With Observations on That Species

Abstract

In her important monograph on "The Molluscan Fauna of the Alum Bluff Group of Florida" Gardner (1926-1950) includes a total of 483 species from the type area of the Chipola Formation: 137 Pelecypoda, 240 Gastropoda, 6 Scaphopoda. Of these, five species of Pelecypoda, six of Gastropoda and one of Scaphopoda were identified with species present in the Recent faunas, while two other pelecypod and three gastropod species are questionably referred to Recent forms. Most of the specimens in the latter group are worn, immature or fragmentary and the author makes clear her belief that adequate material would permit their separation from the modern species to which they have been tentatively ascribed. In view of the low percentage (2.28%) of species certainly identified with elements of the Recent fauna it is of more than usual interest to be able to record the presence in this fauna of Arcopagia (Johnsonella) fausta (Pulteney), a relatively common element of the faunas of southern Florida, the West Indies and the Caribbean area.