4.04. A. SEDGWICK. 
Neo- and Ko-Peripatus; its receptacuium seminis, the 
length of the unpaired part of its vas deferens from Neo-, 
Ko-, and Austro-Peripatus; its distal pedal papillle from 
Capo-, Austro-, and Neo-Peripatus; its spinous pads from 
Capo-, Melano-, and Austro-Peripatus ; its well developed 
coxal organs from Ho-, Neo-, and some Capo-Peripatus. 
Lastly, in the complete separation of its female generative 
tracts (No. 9), and the peculiar method of housing its uterine 
embryos (No. 13), it stands apart from all other species. 
Looked at in this comprehensive way, which is the only fair 
way, there seems to be nothing to be said for placing 
P. Tholloni with Neo-Peripatus. i 
Lastly, let us look at Peripatus cinctipes, which occurs | 
geographically with Capo-Peripatus, and consider whether 
it ought to be separated from this group and placed in a 
special genus. The series of forms found in South Africa 
admittedly present a greater variation in structure than any 
other group. Some of these variations are found throughout 
the group, others are confined to P. cinctipes. It will only 
be necessary for us to consider the latter. These are (1) a 
difference in the number and position of the pedal papillee, 
(2) the presence of a minute receptaculum seminis, (3) a 
difference in the method of opening of the accessory glands 
of the male. With regard to (1) the distal papille vary from. 
the type less than do those of the Andean species of Neo- 
Peripatus amongst one another, and a very similar variation 
is presented by different individuals of the single species of 
Melano-Peripatus. But this is not the only difference from 
the type; the basal pedal papille, so characteristic of the 
Capo-Peripatus in general, are absent. This, though 
important, is not sufficient to justify the establishment of the 
genus Opisthopatus. Nor are the other two; for the 
receptaculum seminis is different to the usual form of that 
organ, and so small that its homology is doubtful, and it may 
easily have been overlooked in other species, and the differ- 
ence in the openings of the accessory glands is parallelled in 
Austro-Peripatus. The absence of the basal pedal papille 
