Marcia

 Marcia fumigata, photographed by Denis Riek.

Belongs within: Veneridae.

Eumarcia is a genus of venerid bivalves found from the Oligocene to the present of Australia and New Zealand. The genus is divided into two subgenera, Eumarcia (Eumarcia) with a superficial lunule and escutcheon and no concentric grooves on the shell surface, and Atamarcia with a well-impressed lunule and escutcheon and generally strong concentric grooves on the shell surface (Marwick 1927).

Characters (from Marwick 1927, for Eumarcia): Shell moderate to large size, oval, margins smooth, pallial sinus ample.

<==Marcia
    |  i. s.: M. planaW26
    |--M. (Eumarcia Iredale 1925)M27
    |    |--M. (*E.) fumigata (Sowerby 1853)K90, M27, K90 [=Venus fumigataM27; incl. V. nitidaM27]
    |    |--‘Eumarcia’ (E.) altilunula Marwick 1927M27
    |    |--‘Eumarcia’ (E.) kaawaensis Marwick 1927M27
    |    |--‘Eumarcia’ (E.) pareoraensis (Suter 1917) [=Macrocallista pareoraensis]M27
    |    `--‘Eumarcia’ (E.) plana Marwick 1927M27
    `--‘Eumarcia’ (Atamarcia Marwick 1927)M27
         |--‘Eumarcia’ (*A.) sulcifera Marwick 1927M27
         |--‘Eumarcia’ (A.) benhami Marwick 1927 (see below for synonymy)M27
         |--‘Eumarcia’ (A.) crassa Marwick 1927M27
         |--‘Eumarcia’ (A.) crassatelliformis Marwick 1927M27
         |--‘Eumarcia’ (A.) curta (Hutton 1873) [=Tapes curta, Paphia (Ruditapes) curta]M27
         |--‘Eumarcia’ (A.) enysi (Hutton 1873) [=Cytherea enysi]M27
         |--‘Eumarcia’ (A.) thomsoni Marwick 1927M27
         `--‘Eumarcia’ (A.) trigonalis Marwick 1927M27

‘Eumarcia’ (Atamarcia) benhami Marwick 1927 [=Venus sulcata Hutton 1875 non Lamarck 1835, Cytherea (Circomphalus) sulcata]M27

References

[K90] Kendrick, G. W. 1990. A Pleistocene molluscan fauna with Anadara trapezia (Deshayes) (Bivalvia: Arcoida) from the Dampier Limestone of Shark Bay, Western Australia. In: Berry, P. F., S. D. Bradshaw & B. R. Wilson (eds) Research in Shark Bay: Report of the France-Australe Bicentenary Expedition Committee pp. 33–48. Western Australian Museum.

[M27] Marwick, J. 1927. The Veneridae of New Zealand. Transactions and Proceedings of the New Zealand Institute 57: 567–636.

[W26] Waghorn, R. J. 1926. The geology of the Ruakokopatuna Valley, southern Wairarapa. Transactions and Proceedings of the New Zealand Institute 57: 226–234.

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