title: A large allantoic sac in the placenta of the spider monkey Ateles geoffroyi.
mesh_terms: D000482:Allantois / Q000033:anatomy & histology* / Q000166:cytology; D000818:Animals; D002427:Cebidae / Q000033:anatomy & histology*; D005321:Extraembryonic Membranes / Q000033:anatomy & histology*; D005260:Female; D010920:Placenta / Q000033:anatomy & histology* / Q000166:cytology; D011247:Pregnancy