396 A. SEDGWICK. 
15. Spermatophores small, oval, with a thin coat. 
16. Skin pigment blue, green, or black, not affected by 
spirit. A certain amount of brown or orange is often present, 
especially on the ventral surface. 
17. Coxal organs variable; usually not well developed. In 
P. Sedgwicki and Moseleyi they are moderately deve- 
loped, and in P. cinctipes well developed. 
18. Crural glands present in most legs of both sexes, 
except possibly in P. cinctipes, in which they have not 
been found by Purcell in the females. 
19. The accessory glands of the male open into the 
terminal part of the vas deferens, except in P. cinctipes, 
in which they open separately between the anus and genital 
opening. . 
The South African group of species presents a greater: 
variation of structure in the selected characters than any of 
the other groups. | 
The variable characters are:—(1) The legs on each side of 
the genital opening, No. 6. (2) The coxal organs, No. 17. 
(8) The size of the ova, No. 11. (4) The presence of a 
trophic vesicle. ‘These vary throughout the group. In 
addition to these we find in P. cinctipes variability in the 
pedal papille, a variability similar to that found in the same 
character in Neo-Peripatus. Moreover, this species is said © 
to possess a minute receptaculum seminis found in no other 
species of the group, and a variation in No. 19. P. cine- 
tipes, on account of its peculiarity in these three characters, 
Nos. 5, 7, 19, has been established by Purcell as a special 
genus, Opisthopatus, which has been accepted by Bouvier. 
I find myself quite unable to admit that the characters men- 
tioned are sufficient to justify the separation of P. cinctipes 
from the rest of the group. The differences are not greater 
than those which separate the Andean-from the Caribbean 
species of Neo-Peripatus, and no one has proposed to 
separate these from one another. 
The assemblage of characters which leads me to assert the 
homogeneity and distinctness of the group are those numbered 
