The<unk>  is a translucent matrix of glycoproteins that surrounds the mammalian oocyte, and its formation is critical to successful fertilization. The size is 15-20 μm. In non-mammals it is called the vitelline membrane or vitelline envelope.
Zona pellucida
Cave of septum pellucidum
Sinus pericranii
External lamina
Tapetum lucidum
Infundibulum
Germinal matrix
Growth cone