A temporary cytoplasmic extension is known as pseudopodium, which means literally 'false foot'. Pseudopodia are powered by microfilaments near the cellular membrane. About half of the internal space in an amoeba contains microfilaments. A pseudopodium contains both granuloplasm and hyaloplasm.
Amoeba proteus, arrows indicate four of the numerous pseudopodia.
Form and structure of the pseudopodia are important taxonomical characters. Depending upon their shape, several types of pseudopodia are distinguished, e.g.:
Lobopodia: more or less finger shaped pseudopodia; most common type of pseudopodia. Lobose amoebae are by far the largest group.
Filopodia: thin and threadlike pseudopodia. These filopodia can branch or anastomose, depending upon taxa.
Reticulopodia: pseudopodia which anastomose (=make contact with another pseudopodium), thus forming a network (reticulum).
Granulopodia: filopodia with a granular structure. The granules are called extrusomes and play a role in capturing prey. These granulopodia can also branch and/or anastomose.
Granuloreticulopodia: filopodia which anastomose and are granulated, known from Allogromia-species.
Axopodia: filopodia supported by regular arrays of microtubules. Amoeboids with axopodia are called Actinopods and are divided into Radiolaria and Heliozoa.
Lamellipodium: broad very thin veil-like pseudopodium