"Formation of the Diblastula of Eucope (one of the Calyptoblastic Hydromedusae) by delamination. A, B, C, three successive stages. ep, ectoderm; hy, endoderm; al, enteric cavity." — Encyclopedia Britannica, 1893

Diblastula

"Formation of the Diblastula of Eucope (one of the Calyptoblastic Hydromedusae) by delamination. A,…