genital groove
From ZooTerms (Dictionary of Invertebrate Zoology)
genital groove: 1. (Arthropoda: Chelicerata) In some female spiders, a cleft posterior to the epigynum into which the fertilization duct opens and through which the eggs pass.
2. (Echiura) A depression, with or without setae, extending from the nephridopore(s) to the mouth on the ventral surface.
