346 ORIGIN OF; LIFE IN AMERICA 



quite a number of genera are now recognised. The most 

 exhaustive account of these remarkable creatures is, no doubt, 

 the monograph recently published by Professor Bouvier. He 

 divides the group into seven genera, of which Peripatus is 

 confined to tropical and sub -tropical America and tropical 

 Africa, and Opisthopatus to Chile and South Africa. This is 

 a most astounding discovery. That a group of these creatures 

 found in tropical South America should be more closely related 

 to another occurring in tropical Africa than to that of Chile, 

 and that the latter should exhibit a more intimate affinity with 

 South African forms than with tropical American ones, is of 

 great zoogeographical interest. Professor Sedgwick,* however, 

 does not share Professor Bouvier's opinion with regard to 

 the intimate relationship supposed to exist between the 

 tropical South American and tropical African, and between 

 the Chilean and South African groups. He thinks they are 

 perfectly distinct from one another. On the other hand, he 

 agrees with Professor Bouvier in the recognition of a group of 

 Onychophora, limited to tropical and sub -tropical America, as 

 distinct from the Chilean group. And this is really the prin- 

 cipal point I wish to draw attention to. 



Professor Bouvierf claims that the Andean species of Peri- 

 patus are the most primitive members of the whole family. 

 He believes that the ancestral stock inhabited a former Pacific 

 continent, and that their immediate descendants took refuge 

 on the astern and western land areas when their original 

 habitat vanished. The whole genus Peripatus, as defined by 

 Professor Bouvier, I may mention again, is found from 

 Mexico in the north, throughout Central America, the West 

 Indies ,and South America as far south as Bolivia. The 

 Chilean species belongs, according to the same authority, to 

 the distinct genus Opisthopatus. 



The genus Peripatus is readily divisible into two sections, 

 the Andean and the Caribbean one. The twelve species be- 

 longing to the former all inhabit the Pacific side of the Andes, 

 except Peripatus eiseni and Peripatus goudoti, which live in 

 Mexico nearly two thousand miles north-westward of the other 



* Sedgwick, A., "Distribution of Onychophora," pp.383 406. 

 t Bouvier, E. L., " Onychophores," L, pp. 64 79. 



