RESUMEN
During a study on the helminth fauna of Liophis anomalus specimens deposited in the Reptile Collection of the Secci6n Zoología Vertebrados, Facultad de Ciencias, Uruguay, a new genus of Opisthogoniminae was found. Paracotyletrema n. gen. is described from the buccal cavity and esophagus of specimens from Departamento de Flores, Uruguay. This new genus differs from the other 2 Opisthogoniminae, Opisthogonimus and Westella, by having much smaller body size; maximum width at level of posterior end of oral sucker; oral sucker length more than one-fourth of body length; oral sucker and acetabulum separated by a distance of about the diameter of pharynx; cirrus pouch length more than half of body length; and testes in completely coincident zones. The type and only species, Paracotyletrema poncedeleoni n. gen., n. sp., is defined by the following diagnostic characters: mean oral sucker length one-third to one-half of body length; cirrus pouch of about body length, contorted, mainly acetabular; large, round testes in nearly adjacent fields, and an ovary nearly adjacent to right testis. Besides the type locality, Paracotyletrema poncedeleoni has been found in L. anomalus specimens from the Departamentos of Artigas and Treinta y Tres; therefore, it has a widespread distribution in Uruguay.