cho·ri·o·al·lan·to·is (kôrē-ōə-lăntō-ĭs, kōr-)
n.
The highly vascular fetal membrane that consists of the fused chorion and allantois, found adjacent to the eggshell in reptiles and birds and constituting the placenta in most mammals.

[TahlilGaran] American Dictionary ▲

chorioallantois
chori·o·allan·toic (-ō-ălən-tōĭk) adj.

[TahlilGaran] American Dictionary ▲