OLIGOCHATA OF TROPICAL HASTERN AFRICA. 228 
ing a narrow space. The sete are strictly paired, and ventral 
in position ; the last segment of the body had four pairs just 
like those of any other segment. The only modification of the 
setze that I could see was that the ventral sete of Segment 
XVII were wanting, being here replaced by the large penial 
sete. 
The male pores are paired. They lie on the border line of 
Segments xvii/xvi11. In one or two specimens a round mass 
was protruded from the pore which I take to be the partially 
protruded bulbus atrii. The male pores are on a line with the 
ventral sete. 
The spermatothecal pore is on the border line of Seg- 
ments xiv/xv. The clitellum I am unable to place. The only 
specially noteworthy matter to be recorded about the epi- 
dermis is that there is no trace whatever of the peculiar sense 
bodies, so like the Pacinian corpuscles of Vertebrates, and so 
commonly met with among the Eudrilide. The circular 
muscular layer can be seen in longitudinal sections to show 
a decidedly bipinnate arrangement of its fibres; these are 
grouped into narrowish tracts which are two to four fibres 
wide. ‘The fibres of the circular muscular layer are laxer in 
their packing than the longitudinal layer. The interspaces are 
filled up by delicate strands of an appearance like that of con- 
nective tissue. The pigment is chiefly lodged in this outer 
layer of muscles. It is disposed in tracts that follow the 
direction of the fibres. Here and there threads of pigment pass 
down through the longitudinal layer following the course of 
the blood-vessels. These are so regular in their arrangement 
that the longitudinal muscular layer is divided up by them into 
a series of squarish blocks. The peritoneum lining the walls 
of the body is also pigmented, and pigment also occurs in the 
peritoneum covering the septa. 
The body-cavity contains in parts numerous corpuscles. 
The septa are, as in so many, if not in all, earthworms, not 
attached to the parietes entirely along the grooves which cor- 
respond to the external metamerism. The first septum divides 
Segments v/v1. It is very delicate. The next six are thick- 
VOL. 386, PART 2.—NEW SER. Q 
