Fig. 3.

Scanning electron microscopic micrograph of P. equorum showing; A: the anterior end had 3 large lips with deep transverse groove the lips were large; crown and prominent, 3 in number, one dorsal and two sub-ventrals. B: the cuticle was with finely striated annulation. C: The tail of the female was conical and slightly attenuated at its distal end. D: The tail of the male was relatively long, and often having a small button-like termination with spicule.