593.11SchaT Schaeffer, Asa Arthur,183- Taxonomy of the amebas with descriptions of Thirty-nine new marine and freshwater species. washugnton; Carnegie Institution of Washington,1926. iii, 116p. ilus., láms. color. 29cm. ( Carnegie Institution of washington. Publication no. 345) A la cabeza del título: "Papers from the Departament of Marine Biology of the Carnegie institution of washington, vol. 24"