瓣鳃纲鳃瓣的基本构造·每个鳃瓣由2个片状的鳃小瓣,称为内鳃小瓣和外鳃小瓣·每个鳃小瓣又由背腹方向纵行的许多鳃丝通过丝间联系连接而成,丝间联系上的小孔称鳃小孔·鳃小瓣前、后端及腹面三面愈合,内面围成的腔称鳃腔,腔内有许多垂直的纵隔连接内鳃小瓣和外鳃小瓣,鳃腔的背面通鳃上腔·鳃丝表面具纤毛,内有血管及支持用的角质杆·水流入外套腔后,经鳃小孔入鳃腔,向背面至鳃上腔,向后流动经出水管排出体外。GOOGLE英文翻译:Lamellibranchiata basic structure of the gill flap. Each of the gill flap from two sheets of the gill flap, known within the gill flap and the outer gill flap. Each gill flap and again by a dorsal longitudinal direction of many of the gill wire through the wire connection between the contact is