@book{bhlitem17464, title = {Studies on the embryology of the Sipunculidae. I. The embryonal envelope and its homologue. ... }, volume = {no. 1}, copyright = {Public domain. The BHL considers that this work is no longer under copyright protection.}, url = {https://www.biodiversitylibrary.org/item/17464}, note = {https://www.biodiversitylibrary.org/bibliography/1927}, publisher = {}, author = {Gerould, John Hiram,}, year = {}, pages = {26}, keywords = {Annelida|Sipunculidae}, }