138 ORIGIN, ETC., OF THE FAUNA. 
to the South African and Australasian groups, and to restrict the original title to the 
South American groups, great additions have been made to our knowledge of this 
Class, mainly by the discovery of new genera, but partly by a more detailed acquaintance 
with species that had been previously described. One practical outcome of these lines 
of research has been rapid development of the classification from the point of view of 
nomenclature, with the result that there appears to be at least eight well-marked 
genera distributed as follows :— 
I. South and Central America and West Indies. 
Peripatus. Tropical America. 
Opisthopatus. Chile. 
II. Tropical and South Africa. 
Peripatus. Congo. 
Opisthopatus. South Africa. 
Peripatopsis. South Africa. 
III. East Indies. 
Typhloperipatus. Abor country, N.E. India. 
Eoperipatus. Sumatra, Malay Peninsula. 
IV. Australasia (including Australia, New Zealand, New Guinea, etc.). 
Paraperipatus. New Guinea, Solomon Islands. 
Peripatoides. Australia and New Zealand. 
Ooperipatus. Australia and New Zealand. 
With exception of Typhloperipatus, described in 1913, these genera were admitted 
by Bouvier in his Monograph of 1907-8. For my present purpose it is immaterial 
that one of the species referred by Bouvier to Ooperipatus has been recently given 
generic rank, under the name Symperipatus by Cockerell, and that the species from 
the Congo and Chile, assigned by the French author respectively to Peripatus and 
Opisthopatus, have been separated from those genera as Mesopertpatus and Meta- 
peripatus by Clark*. The interesting point in this connection is that close 
relationship exists, on the one hand, between the tropical African and tropical South 
American species and, on the other hand, between the Chilian and one of the South 
African forms. Clark’s further proposals regarding the generic and subgeneric 
divisions, to which he refers the tropical American species assigned by Bouvier to 
Peripatus will be referred to later on. 
* Tt will be a nice. controversial question for systematists to settle in the future whether the names 
‘* Congo-Peripatus” and ‘‘ Chilio-Peripatus,” proposed by Sedgwick for these same species, shall be admitted 
as generic terms or not. Clark, perhaps not wisely, disregarded them, probably because Sedgwick, true to his 
colours, expressly disclaimed the intention of putting them forward as generic terms. But since they 
were available as properly published names, future disputation would have been avoided by accepting 
them. 
