Vörös A. szerk.: Fragmenta Mineralogica Et Palaentologica 18. 1996. (Budapest, 1996)

? 0.13 0.16 \ Fig. 2. Dimensions of the anterior fringe fragment of Clavagella (Stirpulina) sp. TUBE DWELLER BIVALVES Clavagella (Stirpulina) belong to the so-called tube-dweller bivalves. The adaptation to tube dwelling in Bivalvia was summarized by SAVAZZI (1982b) and the following description is mainly based on his work. These peculiar bivalves enclose themshelves in secondary calcareous envelopes lying in the soft sediments. Tube dweller bivalves can be found within Gastrochaenacea, Pholadacea and Clavagellacea superfamilies. In the following only the superfamily Clavagellacea will be discussed. KEEN & SMITH (1969) classified the superfamily in the adequate volume of "Treatise on Invertebrate Paleontology". The superfamily Clavagellacea contains only the family Clavagellidae, in which three genera are known: Clavagella Lamarck, 1

81

8 Humphreyia Gray, 1858 Penicillus Bruguiére, 1789 The genus Clavagella contains four subgenera: Clavagella (Clavagella) Lamarck, 1

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8 Clavagella (Bryopa) Gray, 1

847 Clavagella (Dacosta) Gray, 1858 Clavagella (Stirpulina) Stoliczka, 1870