Bipalium vagum Jones & Sterrer, 2005

Figs. 3, 4.

de Luna et al. (2022: 925–935; figs. 1A, 2–3, 5; MEXICO: Campeche, Chiapas, Coahuila, Estado de Mexico, Guerrero, Jalisco, Morelos, Nayarit, Nuevo Leon, Oaxaca, Quintana Roo, San Luis Potosi, Sinaloa, Tabasco, Tamaulipas, Veracruz, and Yucatan).

External diagnosis (de Luna et al. 2022). A small species, up to 5 cm long. Head laterally expanded but not recurved posteriorly, dark brown, sometimes with pigmentation concentrated into two black patches. Dorsal ground color pale brown to tan. Complete black collar at the neck, which extends ventrally and is interrupted at each side of the creeping sole. Dorsum with three longitudinal stripes that start at the collar: a broad median and sharply demarcated black stripe and two lateral broad and diffuse dark-brown stripes. Ventral side light, with white creeping sole distinct but not delineated by longitudinal stripes.

Given its semilunate head plate, Bipalium vagum can only be confused with Bipalium kewense . This species is much smaller than Bipalium kewense and has a complete black collar in the neck region, interrupted in the middle in Bipalium kewense .