OLIGOCHETA OF TROPICAL EASTERN AFRICA. 231 
The species is therefore fairly stout in build. This individual 
had 190 segments. The size of the species is therefore about 
the same as that of Polytoreutus ceruleus, and consider- 
ably less than that of P. magilensis. 
The dorsal surface of the preserved specimens was of a red- 
dish purple, bluer perhaps in some than in others; but there 
was nothing that could be fairly described as ‘ leuchtend 
himmelblau,” a term which Michaelsen uses in writing of 
Polytoreutus ceruleus. The under surface was yellowish. 
The clitellum also was readily distinguishable from the rest of 
the body by its yellowish coloration. The coloration of this 
species was indeed almost, if not exactly, that of the genus 
Eudrilus. 
The prostomium is broad and does not indent in the least 
the buccal segment. This is a generic character, and not 
peculiar to the present species. 
The clitellum occupies Segments xI1v—xviII or in some 
specimens xvit only. It is less developed on the ventral than 
on the dorsal or lateral surface, and it is here only that the boun- 
daries of thesegments, which compose it, are clearly visible. The 
clitellum may in fact be spoken of as ‘ saddle-shaped,” though 
there is really no distinction to be drawn between a clitellum 
of this kind and a “cingulum.” In both the remaining 
species of the genus the clitell 1m lasbeen described as com- 
plete, and consists of an additional segment, the 13th. 
The nephridiopores are lateral in position. 
The sete are paired, and are nowhere deficient except upon 
Segment x11 (see below). The two setz of each of the ventral 
pairs are, however, further apart from each other than are 
those of the lateral pairs. This arrangement was apparent on 
the posterior as well as on the anterior segments of the body ; 
it is not peculiar to the present species, but also characterises 
P. magilensis and P. ceruleus. Michaelsen found no 
setee upon the clitellum of the last-mentioned species; they 
were certainly not absent from this region of the body in 
Polytoreutus violaceus. 
The median genital pores lie, as in the other two species, 
