Centruroides

Centruroides is a genus of scorpions of the family Buthidae. Several North American  species are known by the common vernacular name bark scorpion. Numerous species are extensively found throughout the southern United States, Mexico, Central America, the Antilles and northern South America.[1] Some are known for their interesting patterning or large size (among Buthidae); most if not all fluoresce strongly under ultraviolet  illumination, except after moulting. They contain several highly venomous species, and fatalities are known to occur. The venom of the Mexican scorpion Centruroides limpidus limpidus contains the neurotoxins Cll1 and Cll2.