A Snake Trematode with an Unusual Condition of the Genital Atrium

On April 8, 1948, the writer collected a blue racer, Coluber constrictor ftaviventris Say, along a small creek about three miles south of Lacey-Keosauqua State Park, Van Buren County, Iowa. Upon examination, the mouth was found to contain two trematodes belonging to the subfamily Ochetosomatinae Leao, 1944 (= Reniferinae Pratt, 1902). The trematodes were fully mature adults and were identified as Ochetosoma. vallida (Nicoll, 1911). Nicoll originally described this species as Lechriorchis vallidus from the hognosed snake, Heterodon contortrix Linn., but it was transferred by Talbot ( 1933) to the genus Renifer Pratt because of the lateral position of the genital pore. Byrd and Denton (1938) included this species in their genus, Neorenijer Byrd and Denton, 1938. Kagan (1947) returned this species to the genus Renifer. Leao (1944) showed conclusively that Renifer Pratt, 1902 was a synonym of Ochetosoma Braun, 1901, both being originally described as parasites of the respiro-alimentary tracts of snakes