About Humbertium proserpina (Humbert, 1862)
This species belongs to the genus Humbertium. All species in the genus Humbertium are distinguished by a well-developed penis papilla in their copulatory apparatus. This structure is similar to the penis papilla found in the genus Bipalium. The key difference between Humbertium and Bipalium lies in the entry position of the ovovitelloducts: in Humbertium, ovovitelloducts enter the female atrium from the anterior side, rather than the posterior side as seen in Bipalium.
