4.7S tilCHARD EVANS. 



African, the Neotropical, and the Australian, though 

 he did not consider the differences in character between 

 these groups of sufficient importance to entitle them to the 

 rank of three distinct genera. Consequently all the species 

 then known were described by Mr. Sedgwick in his Mono- 

 graph under the genus Peripatus (15). Later, however, 

 the genus Peripatus, thus constituted, was broken up by Mr. 

 Pocock, and arranged in three genera, corresponding to Mr. 

 Sedgwick's three groups. Mr. Pocock retained the name 

 Peripatus for the Neotropical forms, and gave the names 

 Peripatoides and Peripatopsis to the Australian and 

 Afi'ican forms respectively. 



In the year 1898 Dr. Willey published a complete descrip- 

 tion of a species which he had discovered in New Britain, 

 and gave it the name Paraperipatus Novse-Britannias. 

 Willey, however, considers the three genera formed by 

 Pocock, as well as Paraperipatus, worthy only of sub- 

 generic rank, and prefers along with Mr. Sedgwick to 

 include all the species in one genus. Prior to the publication 

 of Willey's account of P. Novae-Britanniee, M. Bouvier 

 gave a short account of P. Tholloni, for which Dr. Willey 

 justly remarks a new sub-genus must be formed if the other 

 sub-generic names — as he describes them — are to be re- 

 tained ; in other words, he is of opinion that P. Tholloni, 

 from a classiiicatory point of view, is equivalent to any one 

 of the other four sub-genera, a view which is adopted in the 

 present paper, with the difference that Willey's sub-genera 

 are accorded generic rank. Because the species Tholloni 

 is intei-mediate in character between the genus Peripatus 

 (Pocock) on the one hand, and the genus Peripatopsis 

 (Pocock) on the other hand, I propose to give it the generic 

 name Mesoperipatus. 



In addition to the above-mentioned genera a new genus, 

 designated Opisthopatus, has been established by Purcell, 

 to include those African species which in some respects 

 approach the Australian forms (13). 



In a recent number of this Journal, M. Bouvier published 



