124 ORIGIN, ETC., OF THE FAUNA. 
of that country with the southern United States to constitute the Sonoran Region, 
which corresponds with the Mediterranean Region of the Old World. Two more 
genera, Uroctonus and Anuroctonus, are peculiar to the Sonoran, but have not been 
recorded from Mexico. Probably also Plesiochactas and Megacormus from Mexico and 
Guatemala belong to it. The other Sonoran genera, Diplocentrus and Ceutruroides, 
extend far to the south, and link the Sonoran Region with the Antilles and not 
South America. 
South America, the Neotropical Region, is characterised by the family Bothriuride, 
ranging from Peru, Chile, and Brazil to Patagonia; by a large number of genera and 
species belonging to the Chactine, mainly restricted to the northern parts of the 
continent, one genus Broteochactas spreading into Panama; by the Ananterine, a 
peculiar subfamily of Buthide ; by the Buthoid genus Tityus, which spreads through 
Panama and Costa Rica to Mexico; by the peculiar genus of Ischnurine, Opisthacanthus, 
which occurs in Colombia and Panama; and by two peculiar genera of Vajovine, 
Caraboctonus and Hadruroides, ranging from Chile to Ecuador. Thus the southern 
portion of Central America contains Scorpions generically, in some cases specifically, 
identical with those of the northern countries of South America. Ifit be separated 
as a subregion from South America, an immaterial point, it may be defined by the 
absence of a large number of South American genera. 
The affinities of the Antilles are certainly with Neotropical rather than with the 
Sonoran Region. ‘Two Sonoran genera, Diplocentrus and Centrurotdes, it is true, occur 
both in the Greater and Lesser Antilles, but both are found in South America as well. 
The genus Rhopalurus, allied to Centrurotdes, and occurring in Haiti and Cuba, is 
also found in Venezuela, Brazil, and Colombia; Opisthacanthus, inhabiting Colombia 
and Panama, has been recorded from Haiti; and the essentially Neotropical genus 
Tityus exists both in the Greater and Lesser Antilles. One genus, namely Ocelus, is 
peculiar to the Lesser Antilles*. Judged from their Scorpion fauna, therefore, the 
Antilles may be regarded as a subregion of the Neotropical Region, characterised 
mainly by the absence of some conspicuous South American types, ¢. 9. the Chactinie 
and the Bothriuride. 
EVIDENCE SUPPLIED BY THE SCORPIONS FOR A LAND-CONNECTION BETWEEN 
Souto AMERICA AND AUSTRALIA. 
Aithough the following fact has no direct connection with the Scorpion fauna of 
Central America, it is sufficiently interesting to call for mention, since it strongly 
* In my paper on the Scorpions of the West Indies (Journ. Linn. Soc., Zool. xxiv. pp. 374-404, 1893), 
the genera Hadrurus and Brachistosternus were recorded from these islands. The specimens of Hadrurus 
and Brachistcsternus were certainly wrongly labelled. The former, in the Berlin Museum, is, as Kraepelin 
has shown, an Hadruroides from Ecuador; and the specimen of Brachistosternus, one of the Bothriuride, is 
identical with a well-known Peruvian species, 
