36o NATURAL SCIENCE. May. 



one species, Utah, California; ■■'Vejovis, several species, Carolina, 

 Texas, and Utah ; and Cenirunts, two or three species, from 

 Georgia, Florida, Texas, Kansas, and California. Of these 

 Uroctonus does not appear to pass into Mexico; but Hadrnrus 

 hivmtus extends certainly as far as Jalapa, while Vejovis is repre- 

 sented by many species in various parts of Mexico, but does not, so 

 far as is known to me, spread into Nicaragua or Costa Rica. Con- 

 sequently, we must conclude that the greater part of Mexico belongs 

 to the Sonoran Province. The genus Centnmis, which inhabits the 

 southern States, seems to form part of the Neotropical fauna ; for it 

 is represented by several species inhabiting Central America, the 

 West Indies, Colombia, etc. Similarly, Diplocentncs is common to the 

 two regions, since it occurs in Texas, Mexico, the West Indies, and 

 Brazil. But with these exceptions the Neotropical fauna of America, 

 including Panama and all the countries to the south of it, as well as 

 the West Indies, is very distinct from that of all other countries. 

 The following genera are found : — (Diplocentridae) Diplocentnis, two 

 or three species, West Indies, Brazil; (Ischnuridse) ■■'Opisthacanthus 

 one species, Panama, Colombia ; (luridse) ■■'-Hadniroides, four or five 

 species, West Indies, Peru, BoHvia ; ''■'Caraboctonus, one species, Chili, 

 Brazil ; (Chactidse) "^'Broteas, four species, Guiana, Brazil, La Plata ; 

 '■'■Megacormus, one species, Mexico ; ■■'■Broteochactas, three species, 

 Guiana, Venezuela, Colombia ; '''Hadyurochactas, one species, British 

 Guiana; ■'Teuthraustes two species, Eucador ; '■'■'■Chactas and ■■Hetero- 

 chactas, about twelve species, Venezuela, Colombia, Ecuador, Peru ; 

 (Bothriuridae) ■■'•Bothriurns, six or eight species, Peru, Chili, Uruguay, 

 South Brazil ; ■■'Brachistosternns, three or four species, Peru, Chili, Argen- 

 tine ; ■'■Mecocentviis, one species, Brazil ; '■'Phoniocercus, one species, Brazil ; 

 ■■'■Thestylus, one species, Brazil ; ■■'•Centromachiis, one species. Chili ; 

 ■■''Urophoniiis, two species, ChiH, Argentine, Uruguay; (Buthidae) 

 Centrums, many species. West Indies, Colombia, Chili ; '^'Hetevoctcnus, 

 two species, Hayti, Mexico, Brazil ; "^'Tityiis, many species, Mexico, 

 West Indies, Colombia, Brazil, Argentine; ■■'• A naiiter is, one species, 

 Brazil. 



These data show how very specialised is the Neotropical fauna. 

 The Chactidae are coniined to the region, and, with the possible excep- 

 tion of Cercophonius, none of the Neotropical genera of Bothriuridae are 

 found elsewhere. Moreover, three out of the four genera of Buthidae 

 are peculiar ; so, too, is the single genus of Ischnuridae, while the 

 remaining genus of Buthidae occurs elsewhere only in the Sonoran 

 Province of North America. 



Nothing is known of the Scorpions of Patagonia. Darwin, 

 however, tells us that they are found at least as far to the south 

 as the 47th parallel. It is, of course, highly probable that the 

 species of this country will prove to be nearly related to those of 

 ihe Argentine Republic. 



At present our limited knowledge makes it hardly possible to 



