Abstract
Three populations of bivalves from the Egyptian Eastern Desert are systematically described as new species belonging to the family Ostreidae RAFINESQUE. These new species are named Crassostrea canaliculata, Flemingostrea lenticularis, and Arctostrea tenuiplicata of Santonian, Campanian and Maastrichtian age, respectively. The first two species belong to the subfamily Ostreinae RAFINESQUE, and the latter one belongs to the subfamily Lophinae VYALOV.