Diphyllobothrium latum

Diphyllobothrium latum and Paragonimus westermani. Eggs in fecal smear (unstained, low power). Although eggs of these species are frequently confused by inexperienced workers, P. westermani is always larger, and the shell is considerably thickened at the abopercular end. P. westermani also lacks the knob at the abopercular end that is often (though not always) seen in D. latum eggs.