Special sacs developed from the intersegmental septa lodge the developing ova and sperm.
To this category belong certain sacs and pouches.
It is indeed only among the Eudrilidae that the enclosure of the ovaries in septal sacs is at all general.
Sperm ducts and atria as in Limicolae; egg sacs large; body wall thick; vascular system and nephridia as in Terricolae.
The two long ovarian sacs communicate with each other by a transverse bridge before uniting to form the terminal canal.