Nidamental gland

Nidamental glands are internal organs found in some elasmobranchs and certain molluscs, including cephalopods (specifically Decapodiformes and nautiluses) and gastropods.
In cephalopods, nidamental glands are large, paired glandular structures found in the mantle cavity. Accessory nidamental glands may also be present. Nidamental glands are composed of lamellae and are involved in the secretion of egg cases or the gelatinous substance comprising egg masses.