4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



to the region south of the Tropic of Cancer, and of the great majority 

 of them to the southern hemisphere ; only in the West Indies and in 

 Central America do we find an appreciable number north of the 

 equator. 



Another very striking feature is the geographical distinctness of 

 the systematic units. Nowhere, so far as we know, do species of the 

 Peripatidse and of the Peripatopsidae occur together. The two sub- 

 families of the Peripatidse are separated by the entire breadth of the 

 Indian Ocean. 



In the subfamily Peripatinse, Mesoperipatus is separated from 

 Oroperipatus, Macroperipatus, Epiperipatus, Plicatoperipatus and 

 Peripatus by the expanse of the Atlantic Ocean ; Plicatoperipatus is 

 isolated on the island of Jamaica where, however, Peripatus is also 

 found ; Oroperipatus occurs almost exclusively west of the watershed 

 between the Pacific and the Atlantic in Central and South America ; 

 Peripatus, however, also occurs within its territory ; Macroperipatus 

 and Epiperipatus, both generally distributed over tropical America 

 east of the Andes, occur over practically the same area, though the 

 former is absent from Tobago and Grenada where the latter occurs ; 

 Peripatus is found with them over a small area in northern Venezuela. 

 Peripatus alone occurs in the Antilles, except on Jamaica, where 

 Plicatoperipatus also is found, and on Cuba, Grenada, Tobago and 

 Trinidad, from which islands it is absent. 



The two subfamilies of the Peripatopsidae are entirely separate in 

 the Australian region, one (Peripatopsinse) being confined to New 

 Guinea and the adjacent islands, the other (Peripatoidinse) occurring 

 in Australia, Tasmania and New Zealand, though both exist together 

 in South Africa ; in each subfamily the genera found in South Africa 

 represent a systematic type markedly different from that found 

 further to the east. The subfamily Peripatoidinse is represented in 

 Chile. 



We are thus able to recognize among the onychophores traces of 

 a zonal distribution such as is suggested by many other types, best 

 marked in the east, the Peripatidse being equatorial (the Malay Pen- 

 insula and Sumatra, central Africa and tropical South and Central 

 America), the Peripatopsinse intermediate (New Britain, New 

 Guinea and Ceram, Natal, and the adjacent portions of Cape Colony) , 

 and the Peripatoidinse austral (Australia, Tasmania and New Zea- 

 land, Natal and the Cape Colony, and Chile) . 



