Centruroides exilicauda - previously Centruroides sculpturatus. This small scorpion is typically straw-coloured, but can be found in a variety of colour morphs. A typical bark scorpion, it is most often found under rocks, bits of loose tree bark, or crevices in walls. It has potent venom which has resulted in a number of confirmed deaths. It is the most dangerous scorpion in the US. Although C. exilicauda is not difficult to maintain in captivity, it is not a species for beginners.
Centruroides gracilis. Also known as the slenderbrown scorpion. It is one of the largest of the bark scorpions, up to 4 inches long, but is more slenderly built than other Centruroides species. It is native to tropical areas in Central America, Mexico and Florida. Like all of the bark scorpions, the Florida bark scorpion is nocturnal and seeks shelter during the day under loose pieces of bark. They are very hardy & make good captives for beginning scorpion keepers. The Florida bark scorpion's sting is not medically significant.