Choeradoplana albonigra (Riester, 1938) A diagrammatic reconstruction of copulatory apparatus of holotype from sagittal sections B photomicrograph of a sagittal section of the unpaired portion of the prostatic vesicle and proximal section of male atrium of specimen F4024. Arrow points the small ring-shaped horizontal fold communicating prostatic vesicle with male atrium C diagrammatic reconstruction of copulatory apparatus of specimen F4081 from sagittal sections D photomicrograph of a sagittal section of the female atrium of specimen F4081. Abbreviations: cm common muscle coat, co common glandular ovovitelline duct, dd decussate dorsal cutaneous muscles, dm diagonal decussate muscles, e eye, ej ejaculatory duct, ep esophagus, er erythrophil secretion, fa female atrium, fd female genital duct, g gonopore, i intestine, lc longitudinal cutaneous muscles, ma male genital atrium, mk Muskelgeflecht (Graff, 1899), mo mouth, o ovary, ov ovovitelline duct, ph pharyngeal pouch, pp penis papilla, pv prostatic vesicle, px pharynx, rg rhabditogen glands, r retractor muscle, sb subintestinal transverse muscles, sd sperm duct, sg shell glands, sk sunken longitudinal cutaneous muscles, sm spermatophore, sn subneural transverse muscles, sp supra-intestinal transverse muscles, t testis, vi vitellaria, vn ventral nerve plate.