The purpose of this application, under Articles 78.1, 78.2.3 and 81 of the Code, is to conserve the long and continuing usage of the specific name Crotalinus catenatus Rafinesque, 1818 (currently Sistrurus catenatus) for a species of pygmy rattlesnake by designation of a neotype. In addition, in order to will conserve the nearly equally long and continuous usage of the name Crotalus tergeminus Say in James, 1822 (currently Sistrurus tergeminus or Sistrurus catenatus tergeminus) for another pygmy rattlesnake, the Commission is asked to designate a neotype for this nominal species also. Newly found evidence indicates that the name Crotalinus catenatus was based on a specimen of C. tergeminus, and to conserve the names of both nominal taxa designation of neotypes for each is required.