HELMINTHS OF THE PRAIRIE RATTLESNAKE, CROTALUS-VIRIDIS-VIRIDIS (SERPENTES, VIPERIDAE), FROM WESTERN SOUTH-DAKOTA

One hundred prairie rattlesnakes, Crotalus viridis viridis, from weste rn South Dakota were examined for evidence of helminth parasites. Twen ty-one percent were infected with 1 of 6 parasite species. The followi ng species were recovered: Manodistomum sp., Mesocestoides sp., Physal optera sp., 2 different species of oligacanthorhynchid acanthocephala, and an unidentified species of acanthocephalan. The occurrences of ol igacanthorhynchid acanthocephala and Manodistomum sp. in C. v. viridis represent: new host and locality records. A natural infection of Meso cestoides sp. tetrathyridia is documented in this host for the first t ime.