Lorica - body form Protozoans

It is a covering which unlike the theca fits loosely around the organism. It is a cup, bell or vase-like structure with one opening through which protrude the animal's appendages or the anterior part of the body. In solitary protozoans, the lorica may or may not possess a stalk. Cothumia which occur in couples, are contained in tectinous lorica and are stalked.

Figure: Cothurina

The protozoan nuclei are membrane bound, diverse in structure and method of division. Two basic types are found, vesicular with considerable\amount of nucleoplasm and the other compact. When more than one nucelus is present they are usually alike except in ciliates, where a massive compact macronucleus and one or more compact macronuclei are present. Cytoplasm can be distinguished as ectoplasm and endoplasm.

Ectoplasm appears transparent under light microscope and bears the base of the flagella or ciliia. The endoplasm appears granular and contains the nucleus and cytoplasmic organellps. The ectoplasm is more rigid and is in the gel state of a colloid while the endoplasm is in the sol or more fluid state.