DISTRIBUTION AND CLASSIFICATION OF ONYCHOPHORA. 381 
he discovered in New Britain, and he showed that it possesses 
characters peculiar to itself which sharply differentiate it from 
all other known species. In 1901 Evans described three new 
species which he had found in the Malay Peninsula, and he 
showed that they possessed some peculiar features which are 
also presented by the Sumatran species, and are not found in 
any of the other known species. He thus established the 
reality of the Sumatran species, which I had been obliged to 
leave doubtful, and definitely established a new group of 
species from the Malayan Region distinct from the species of 
the other great geographical groups. 
Purcell (1899) made a thorough and most valuable revision 
of the South African species, and discovered that one of them 
differs from the rest in points which seemed to justify the 
creation of a special genus Opisthopatus for its reception. 
In addition to this work, important observations were made 
upon the Australasian species by Fletcher and by Dendy, the 
last of whom discovered that some of the species from this region 
are normally oviparous; by Miss Sheldon on the development 
of a New Zealand species ; by Sclater on the development of 
a Neotropical species; by Willey and Evans on the develop- 
ment of the New Britain and Malayan species respectively. 
With this work, however, I am not so much concerned here, 
excepting in so far as it adds to our knowledge of the remark- 
able variety in the structure of the ovum and early develop- 
ment in the genus. 
In 1894 Pocock! definitely exalted three of my specific 
groups to generic rank, and named them: Peripatus (the 
American species), Peripatopsis (the South African), and 
-Peripatoides (the Australasian). This example was 
followed, and the result is that we now have not only seven 
genera, viz. Peripatus, Peripatopsis, Peripatoides, 
Paraperipatus (Melanesia), Hoperipatus (Malaya), 
Ooperipatus (Australasia), Opisthopatus (South Africa), 
1 R. J. Pocock, ‘‘ Contribution to our Knowledge of the Arthropod Fauna 
of the West Indies: II. Malacopoda or Prototracheata,”’ ‘Journ. Linn. Soe.’ 
(Zool.), xxiv, 1894, p. 518. 
