Gymnophryidae is a small family of amoeboids that lack shells and produce thin, reticulose pseudopods. These contain microtubules and have a granular appearance, owing to the presence of extrusomes, but are distinct from the pseudopods of Foraminifera. They are included among the Cercozoa (along with Lecythium), but differ from other cercozoans in having mitochondria with flat cristae, rather than tubular cristae.