FIGURE 12 in A review of the genus Eclipidrilus (Annelida: Clitellata: Lumbriculidae), with description of a new species from western North America

FIGURE 12. Eclipidrilus frigidus (A, C–E, Big Spring at Bassets, California), (B,F, Jackass Creek, California). A—penial sac, with penis extruded through the papilla, into the sac; sagittal section of a mature worm. B—ectal end of penial structure of a nearly mature worm, with partially developed sac and papilla, and irregular lumen; sagittal section. C—penial structure near ectal end, showing fibrous epithelium; sagittal section of a mature worm. D—outer (longitudinal­diagonal) muscle layer of atrial ampulla, sagittal section of a mature worm. E—atrial ampulla, transverse section of a mature worm. F—ectal duct of spermatheca, showing ectal expansion of duct, sagittal section of a nearly mature worm. Abbreviations: lm—longitudinal­diagonal muscle; mu—muscle; pe—penis; pp—penial papilla; pr—prostate gland; ps—penial sac; tm—transverse­circular muscle. Scale bars 50 µm.