Penis, Wallaconchis graniferum, not evaginated and opened, Philippines, Bohol (A–B) [5762] (PNM 041226) (C) [5761] (PNM 041228). A Penis invaginated inside the penial sheath opened to reveal regions of penial hooks, scale bar 200 μm B Most proximal region of penis invaginated inside the penial sheath opened to reveal penial hooks, scale bar 200 μm C Penis invaginated inside penial sheath (both opened to reveal the penial hooks), scale bar 0.5 mm. Abbreviations (from proximal to distal): ph proximal hooks (first penial region) lh long slender hooks (second penial region) sh short hooks (second penial region) nh no hooks (gap) dh distal hooks (third penial region).