TREMATODOS DE LAS CULEBRAS DE AGUA DULCE DE MEXICO. I.

Resumen

This paper deals with some intestinal fresh water snakes of Mexico; one species, Cercorchis kinosterni Byrd, 1936, is redescribed and two new species are described, besides, one in the genus Renifer and the other in the genus Cercorchis.
According to Byrd and Denton's revision (1938) of the sub-family Reniferinae, our species, Renifer brevicoecum n. sp., is within the genus Renifer s. tr., differs from the six species already known, in the lack of oesophagus, the little development of the intestinal
caeca , the location of the cirrus pouch and the way in which the vitellaria a re disposed.
Cercorchis thamnophidis n . sp. differs fundamentally from all other known species which lack pre-pharynx, in the distribution of the vitellaria and in the length of the intestinal caeca , for, in the species so far described, the caeca extends beyond the posterior
testicle, while in this species they reach only the anterior border of the anterior testicle. Other differential characters are the length of the eggs and the total length of the body.