Pseudocoelom body cavity is false coelom, derived from embryonic blastocoel, eg, Aschelminthes (Ascaru). In pseudo coelomates, there is a liquid filled space in which body organs float. Eucoelom or true coelom lines with two layers of mesoderm, eg, earthworms. It may be schizocoelom or enterocoelom. Schizocoelom is the true coelom, originated by splitting of mesoderm and its enlargement to form the cavity, eg, Annelida, Arthropoda, Mollusca. Haemocoelom is the true coelom, filled with blood. It is found in arthropods, some annelids and molluscs, where the circulatory system is open type (with blood sinuses and lacunae).