Atelidae: A family of New World Monkeys in the infraorder PLATYRRHINI, comprising two subfamilies: ALOUATTINAE and ATELINAE.Alouatta: A genus of the subfamily ALOUATTINAE, family ATELIDAE, inhabiting the forests of Central and South America. Howlers travel in groups and define their territories by howling accompanied by vigorously shaking and breaking branches.Cebidae: A family of New World monkeys in the infraorder PLATYRRHINI, consisting of nine subfamilies: ALOUATTINAE; AOTINAE; Atelinae; Callicebinae; CALLIMICONINAE; CALLITRICHINAE; CEBINAE; Pithecinae; and SAIMIRINAE. They inhabit the forests of South and Central America, comprising the largest family of South American monkeys.Oxyuroidea: A superfamily of parasitic nematodes consisting of several genera. ENTEROBIUS, which occurs in humans, and Oxyuris, which occurs in horses, are two of the most common. Other genera are: Skrjabinema, Passalurus, Dermatoxys, and Probstmayria.Oxyuriasis: Infection with nematodes of the superfamily OXYUROIDEA.