ALGUNOS TREMATODOS INTESTINALES DE LOS MURCIELAGOS DE MEXICO I.

Resumen

ln the months of December 1939 and January 1940 we collected some trematodes parasites in the intestines of a bat Tadarida brasiliensis Geoffroy, which belonged to three different genera: Plagiorchis, Limatulum ancl Lecithodendrium.
Ten of the Trematodes found belonged to the species Plagiorchis (Plagiorchis) vespertilionis (Má¼ller, 1780) of which we make a redescription; and mention for the same a new host and a new area of dispersion.
The three specimens representing the genus Limatulum are described as a new species. Limatulum scabrum n. sp. differs from
Limatulum limatulum (Braun, 1901) because it has no spines in the cuticle; from L. oklahomensis Macy, 1931 chiefly because the ovarry is post-testicular and post-acetabular and also because all its measurements are smaller; from L. gastroides Macy, 1935 because it presents no spines in the cuticle and because the ovary is post-acetabular and from L. diminutum Chandler, 1938 because the ovary is postacetabular and also on account of the general measurements.
The five species which up to now from this genus have been grouped in a key for an easier determination.