1.Unlike other molluscs, bivalves lack a radula and feature labial palps, which carry food from the gills to the mouth.

1.与其他软体动物不同的是,双壳贝缺乏齿舌,有瓣,可将物由鳃部.

2.The mandibles are usually lost, the labrum is reduced to a narrow transverse sclerite, and the labium is a small flap ( though its palps retain quite large).

2.上颚消失，上退化为一条窄横片，下退化为一小片（下须发达）。