Discipline: Veterinary Medicine
Adult specimen of Platyamphistoma polycladiforme (Nasmark, 1937) and Glyptamphistoma paradoxum (Nasmark, 1937) from the stomach of the hippopotamus (Hippopotamus amphibius) were prepared and examined histologically under light microscopy (LM) and their tegumental surfaces under scanmng electron microscopy (SEM). Both species are redescribed based on observations made by these methods. The species are characterized as follows: Platyamphistoma polycladiforme body flattened dorsoventrally, thickest and convex dorso- and ventro-medially and thin laterally: presence of a U-shaped postero-dorsal notch: pharynx of the paramphistomum type; terminal genitalium of the sellsi type; acetabulum of the nilocotyle type; anterior papillae long with ciliated bulb-like branches, and dome-shaped non-ciliated papillae around genital pore and acetabular opening Gyptamphistoma paradoxum body almost cylindrical with transverse ridges or hoops, pharynx of the paramphistomum type, esophagus with posterior bulb, terminal genitalium of the epiclitum type, and acetabulum of the nilocotyle type; anterior papillae of variable height (bump-like to thumb-like), non branching and ciliated; dome-shaped non-ciliated papillae around genital pore and acetabular openings, and clusters of minute papillae on transverse ridges. These characters are accompanied by illustrations as line drawings and microphotographs. The possible function of tegumental papillae is discussed.