Fig. 1
From: Ultrastructure of oogenesis in imposex females of Babylonia areolata (Caenogastropoda: Buccinidae)
General scheme of imposex evolution in prosobranchs (adopted from Stroben et al. 1992a). Thick lines indicate imposex stages of B. areolata. ac aborted capsules, cg capsule gland, gp genital papilla, obc open bursa copulatrix, ocg open capsule gland, ocv occlusion of vulva, p penis, pd penis duct, pr prostate gland, t tentacle, vd vas deferens, vdp vas deferens passage into capsule gland, vds vas deferens section