egg mass A large number of eggs encapsulated in a gelatinous matrix or a large number of such structures that are attached together. The egg mass of an oceanic squid can be a large, fragile gelatinous ball carrying many thousands of eggs. In contrast, the egg mass of a neritic squid (loliginid) can be composed of very tough capsules each carrying several hundred eggs with many capsules attached together at their bases and to the substrate to form an egg mass. todo - mireot egg case anatomical cluster