The two pinworms parasitic in Man are studied and compared. Enterobius vermicularis
(L., 1758) has the larger spicule (100 to 140 micron). E. gregorii Hugot, 1983 has
the shorter spicule (70 to 80 micron). The two species can also be differentiated
by the cuticular ornamentation associated to the cloacal opening in the males.