Hymenolepis spp.

Hymenolepis nana. Egg in feces (unstained, high power). The clear, thin-shelled eggs of H. nana are spherical to subspherical in shape and measure about 30 to 47 µm in diameter. The six-hooked oncosphere is enclosed in a membrane that has two polar thickenings from each of which arise four to eight filaments that occupy the space between the embryo and outer shell.