Stylochus neapolitanus (MNCN 4.01/3281 to 3334). Histological sections are postero-anteriorly oriented: A. Dorsal view of a living specimen; B. Ventral view; C. Histological section of the male copulatory organs; D. Histological section of the female apparatus; E. Sagittal reconstruction of the reproductive system. Abbreviations: cg, cemental glands; eg, extravesicular glands; ev, external vagina; fp, female pore; i, intestine; iv, internal vagina; ma, male atrium; mp, male pore; pp, penis papilla; pv, prostatic vesicle; sv, seminal vesicle; vd, vas deferens.