@book{bhlitem31931, title = {Proceedings of the American Philosophical Society held at Philadelphia for promoting useful knowledge }, volume = {v. 18 (1878-1880)}, copyright = {NOT_IN_COPYRIGHT}, url = {https://www.biodiversitylibrary.org/item/31931}, note = {https://www.biodiversitylibrary.org/bibliography/7023}, publisher = {Philadelphia, American Philosophical Society, }, author = {American Philosophical Society.}, year = {1878}, pages = {624}, keywords = {Learned institutions and societies|Pennsylvania|Periodicals|Philadelphia|Science}, }