Genital opening subterminal behind the last pair of legs; oviduct with receptaculum seminis, without receptaculum ovorum; unpaired part of vas deferens very short; accessory glands two, opening medianly and dorsally.
Genital opening between the penultimate legs; oviduct with receptacula seminis and ovorum; unpaired part of vas deferens long; male accessory glands two, opening medianly between the legs of the last pair.
Genital opening subterminal, behind the last pair of fully developed legs; oviduct without receptacula seminis or receptacula ovorum; the terminal unpaired portion of vas deferens short.
Genital opening between the legs of the penultimate pair; oviduct provided with receptacula seminis and ovorum; unpaired part of vas deferens long and complicated; accessory organs of male opening at the sides of the anus.
In Scutigera there are seven unpaired dorsal stigmata, each leading into a sac whence a number of air-holding tubes project into the pericardial blood-sinus.