“双壳类”用英语怎么说

乔里富组内的化石主要是双壳类和砂壳有孔虫.The fauna in the Joli Fou consists of bivalves and arenaceous forams.调查期间采到的软体动物已鉴定52种,其中腹足类45种, 双壳类7种.Among 52 species of mollusca identified , 45 were gastropods, 7 were bivalves....