An nonvascular extraembryonic basement membrane that forms on the inner surface of the trophectoderm during placenta morphogenesis and is secreted by the distal parietal endoderm; required for the maternofetal exchange of nutrients and is important for the postgastrulation development[MP]. a thick multilayered basement membrane between the parietal endoderm cells and the trophoblast cells. [ MP:0003954 http://dx.doi.org/10.1007/BF00184752 ]

This is just here as a test because I lose it