SEM of cystacanths of Neoandracantha peruensis from ghost crabs, Ocypode gaudichaudii, from the Pacific Ocean off Peru. 18. A spine from the posterior field of the foretrunk spines. 19. A gallium cut cross-section of a spine showing its spongy structure. 20. The posterior end of a female hindtrunk showing the subterminal position of the gonopore (lower left). 21. Micropores at the foretrunk of a female specimen. 22. Eggs in the body cavity of a female at the foretrunk-midtrunk junction. 23. A small cluster of eggs showing their different developmental stages.