"Diagrammatic representation of development of Oscarella lobularis. Bl., Free-swimming blastula with flagella; G., gastrula settled down. Next figure shows folding of inner layer (En.); Ec., outer layer. Lowest figure shows radial chambers (R.C.); Mesogloea (Mg.); inhalant pore (P.); exhalant osculum (O.)." -Thomson, 1916

O. Lobularis

"Diagrammatic representation of development of Oscarella lobularis. Bl., Free-swimming blastula with…