The white-headed marmoset (Callithrix geoffroyi), also known as the tufted-ear marmoset, Geoffroy's marmoset, or Geoffrey's marmoset, is a marmosetendemic to forests in eastern Brazil, where it is native to Bahia, Espírito Santo, and Minas Gerais, and introduced to Santa Catarina.[2] It is known as the sagüi or sauim in Brazil.[3] Its diet consists of fruits, insects, and the gum of trees.[4] It is a host of Pachysentis lenti an acanthocephalan intestinal parasite.[5]