122 ORIGIN, ETC., OF THE FAUNA. 
GENERAL FEATURES OF THE SCORPION FauNA OF CENTRAL AMERICA. 
The nine genera of Scorpions certainly ascertained to be Central American are 
faunistically assignable to a northern category, a southern category, and a category 
which is both northern and southern. 
To the southern category belong Opisthacanthus, occurring in Panama and Colombia ; 
Broteochactas, also found in Panama and the northern countries of South America 
(Guiana, etc.); and Zityus, which ranges all over South America from the Argentine 
northwards and is found in Panama, Costa Rica, and Mexico. ‘The Mexican species, 
however, is very little known. It is not closely allied to the species from Costa Rica 
and Panama, which are identical with, or very nearly related to, species from the 
Amazons, Demerara, etc. Similarly, the species of Opisthacanthus and Broteochactas 
occurring in Panama are the same as species found in South America. 
To the northern category belong Hadrurus and Vajovis, which extend from the 
Southern States of North America into Mexico, Vajovis being one of the dominant 
Scorpions in the latter country. It is interesting to note the wide geographical 
severance between these two and their nearest allies, Caraboctonus and Hadruroides, 
which inhabit Ecuador, Bolivia, and Chile. Also to this northern category must be 
referred the two genera of Megacormine, Megacormus and Plesiochactas, which are 
found in Mexico (Vera Cruz, Cordova), the latter extending to Guatemala. Their 
nearest allies are the Chactine of tropical South America. 
To the category which is both northern and southern in distribution belong the 
genera Diplocentrus and Centruroides. ‘The former ranges from Texas into Mexico, 
but not, so far as is known, to the south of the latter country in Ceutral America. 
Nevertheless, it is found in the Greater and Lesser Antilles and in the northern part 
of South America (Brazil). Centruroides, on the other hand, occurs in the southern 
states of North America, throughout Central America, in South America as far down 
as Chile along the western side, in Brazil, and in the Greater and Lesser Antilles, 
Thus of the Central American genera only four occur in the Antilles, Tityus, 
Centruroides, Diplocentrus, and Opisthacanthus. 
Iwo of the above-mentioned genera, Opisthacanthus and Diplocentrus, are of 
outstanding interest from the geographical point of view, because of the singular 
distribution of the subfamilies to which they belong. 
Opisthacanthus is unmistakably related to the tropical and South African genus 
Opisthocentrus. The generic distinction between the two is not, indeed, always 
admitted. ‘Tropical Africa is also the home of several more genera of the subfamily 
Ischnurine, while others occur in Madagascar and South Asia as far east as 
Australasia. The kinship between the African and the solitary monotypical tropical 
American genus suggests that South America received this element of its fauna by 
means of a direct land-connection with Africa. 
