Of the world’s 36 species of known rattlesnakes, surely the black-tailed rattlesnake, (Crotalus molossus), would win one of the top prizes for sheer beauty. My wife and I spent half and hour watching and photographing this unagressive, beguiling individual. We found it basking, suspended several feet off the ground among tree branches in a walnut – velvet mesquite bosque. This one was large for its kind, close to 48 inches in length.