230 R. I. POCOCK [march 



severance from Africa was effected, and, according to our hypothesis, 

 this migration took place in Oligocene times. Hence, if a land con- 

 nection between South Africa and South America existed at any time 

 during or after the Oligocene, scorpions of this genus might have 

 crossed from one continent to the other. That Africa and not South 

 America was the original home of the genus is shown by the existence 

 of many species in the former country and of many allied genera in 

 the same and other areas of the Old "World, while the single species 

 that South America possesses is the only representative of the family 

 found in the New World. 



The same Hue of argument might be adopted to explain the 

 occurrence of the Pedipalp Damon in the Ethiopian and Neotropical 

 regions, were it not that the genus is not known to inhabit Madagascar. 

 Possibly it may in the future be found in this island, but if not, its 

 absence, as already shown, will indicate that it entered or became 

 evolved in South Africa after the formation of the Mozambique 

 channel ; and since this event is believed to have taken place about the 

 Plicoene period, and assuming the present distribution of Damon in 

 South America and South Africa to be due to the existence of a southern 

 land connection between the two continents it inhabits, it seems clear 

 that the connecting bridge had not subsided, at all events, before the 

 beginning of the Pliocene. 



The available evidence then seems to show that the Neotropical 

 region owes the bulk of its fauna to North America, and that certain 

 elements in it may have come from South Africa. Again, the evidence 

 appears to me to be in favour of the hypothesis that it was peopled 

 with the ancestors of its existing species of scorpions, Pedipalps, and 

 Solpugas during the Tertiary epoch. 



The West. Indies seem to have acquired their fauna from two 

 sources. The Solifugae and Thelyphonidae probably came from Central 

 America vid Cuba ; and a land connection between this island and 

 Yucatan is believed to have existed in the Pliocene and probably in 

 the Plistocene as well. Some of the scorpions and the species of 

 Admetus of the fuscimanus type appear to have travelled by the same 

 route ; while other scorpions and the species of Admetus of the pal- 

 matus type seem to have entered the sub-region from the south vid 

 Venezuela or Guiana. 



In a paper upon the geographical distribution of scorpions already 

 referred to, I pointed out that the area of the earth's surface to 

 which these animals are now restricted might be divided into the 

 following regions : — 



1. Mediterranean, including South Europe, North Africa from 



Senegambia to Nubia, Arabia, Asia Minor, Persia, Afghan- 

 istan, etc., and North-Eastern China. 



2. Ethiopian, including Africa south of Senegambia and Nubia, 



and Madagascar. 



