Description: English: Muscle layers of pharynx in cross section. A, Planariidae; B, Dendrocoelidae. Abbreviations: epe, external epithelium; epi, internal epithelium; me, external muscle layer; mi, internal muscle layer. Date: 10 September 2014, 15:06:55. Source: Freshwater planarians (Turbellaria) of North America (1972) : This file comes from the Biodiversity Heritage Library, and is available online at biodiversitylibrary.org/item/22578. This tag does not indicate the copyright status of the attached work. A normal copyright tag is still required. See Commons:Licensing. Deutsch | English | español | français | italiano | 日本語 | македонски | Nederlands | polski | +/−. Author: Roman Kenk.