NO. I DISTRIBUTION OF THE ONYCHOPHORA CLARK 1 5 



archipelago, exclusive, however, in the south, of Trinidad, Tobago 

 and Grenada, which still remained united to the mainland. 



These fundamental changes in the geological structure of tropical 

 America induced corresponding alterations in the environment of all 

 the terrestrial organisms, and it was possibly as a result of these 

 alterations in environmental conditions that the two subgenera 

 Macroperipatus and Epiperipatus, both more specialized and econom- 

 ically more efficient than the parent type, were given off from 

 Peripatus. 



The effect of the economically more efficient Macroperipatus and 

 Epiperipatus upon the parent type, Peripatus, was the same as had 

 been the effect of Peripatus upon Or op eripatus; Peripatus disap- 

 peared from every situation which they were able to reach. 



Thus Peripatus disappeared almost completely from continental 

 South and Central America, persisting only in the mountains of 

 western Venezuela, Colombia, Panama, and Costa Rica, from which 

 territory we know the following species — Peripatus (Peripatus) 

 sedgwicki, Caracas, San Esteban, La Moka, Las Trincheras, and La 

 Guayra, Venezuela ; Peripatus (P eripatus) brolemanni, Tovar, Raxto 

 Casselo, and Puerto Cabello, Venezuela ; Peripatus (Peripatus) 

 bouvieri, Boca del Monte, near Bogota, Colombia ; and Peripatus 

 (Peripatus) ruber, Rancho Redondo, Costa Rica, and Lino, near 

 Bouquete, in the Province of Chiriqui, Panama. But the very process 

 which caused Peripatus to disappear almost completely from the 

 mainland of South America resulted in making it the characteristic 

 type in the Antilles from Jamaica and Haiti eastward and southward 

 to and including St. Vincent, for, thanks to the water barrier, 

 Macroperipatus and Epiperipatus were not able to reach these islands, 

 though they could, and did, reach Trinidad, Tobago, and Grenada, 

 which at this time were a part of the mainland. 



It is possible that the origin of Macroperipatus was subsequent to 

 that of Epiperipatus, so that it was prevented from reaching Tobago 

 and Grenada by the separation of those islands from the mainland 

 after the intrusion of Epiperipatus. 



The subgenus Plicat op eripatus appears to be, so far as we are able 

 to see at present, of local origin in the island of Jamaica ; it is quite 

 possible, however, that it occurs in Haiti also. 



The occurrence of Epiperipatus upon Grenada, Tobago, and Trini- 

 dad, and. of Macroperipatus upon Trinidad, the very close relationship 

 between the species of Epiperipatus upon Tobago and Trinidad, 1 and 



1 Piccole Note su degli Onychophora. Zool. Anzeiger, Bd. 42, Nr. 6, S. 253- 

 255. 18 Juli 1913- 



