Holocene and recent shallow soft-bottom mollusks from the Northern Gulf of Thailand area: Bivalvia

The bivalves recovered from the Holocene Bangkok Clay in the Lower Central Plain of Bangkok along with those obtained from modern shallow bottoms in Phetchaburi coastal area are recorded and described. The bivalve assemblages of the Holocene Bangkok Clay appear to parallel the Recent ones recovered at sea, from intertidal and shallow infralittoral, predominantly muddy, substrates. Arcoidea, Galeommatoidea, Tellinoidea and Veneroidea are the most diverse groups, often with species that occur abundantly. This paper covers 225 species, 35 out of them unidentified and, at least partly, previously undescribed. The species treated are complemented with taxonomic remarks when necessary and with information on respective ecological requirements if available. Except for a few species represented only by fragmented shells, all are illustrated. A list of references to the mollusk fauna of the Indo-Pacific Region is also given in order to provide facilities to the reader.