Cytostome

Label 7 indicates the cytostome in a typical Ciliate

A cytostome (cyto- meaning cell and stome- meaning mouth) or cell mouth is a part of a cell specialized for phagocytosis, usually in the form of a microtubule-supported funnel or groove. Food is directed into the cytostome, and sealed into vacuoles. Only certain groups of protozoa, such as the ciliates and excavates, have cytostomes. Such examples include Balantidium coli - a ciliate. In others, and in cells from multicellular organisms, phagocytosis takes place at any point on the cell or feeding takes place by absorption.