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 eastern 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,” I., pp. 64—79. 
