SEM of cystacanths of Profilicollis altmani from Emerita analoga on the Peruvian coastline, Lima. 11. Micropores from the mid-trunk region. 12. A fully extended tail. 13. Lateral view of a partially retracted tail. 14. Posterior view of the partially retracted tail showing invagination point and the coarse corrugated texture of the cuticular surface. 15. Genital orifice of a female gonopore at the posterior end of a fully extended tail. Note the thick un-corrugated lips. 16. A cluster of developing eggs in a female cystacanth.