1886. ] LITTLE-KNOWN EARTHWORMS. 313 
generative orifices is certainly shown by the series of variations in 
Perionyx described in the present paper. When the male generative 
pores, as in var. no. I, are placed very far forward, the clitellum also 
moves forward; on the other hand, when the male generative pores 
are situated further back, e. g. in segment 19, the clitellum likewise 
changes its position and occupies segments 15-18. 
In both these instances it will be noted that the relations of the 
male pore to the clitellum remain the same, although both struc- 
tures have shifted their position; in both cases, as in the normal 
condition, the male generative pore occupies the first segment after 
the clitellum. This fact would at first sight appear to be a strong 
argument in favour of Perrier’s scheme of classification; but in the 
first place the clitellum extends in var. No. | on to the left half of 
segment 16, and in the second place one variety (No. 3) was 
distinctly ‘ intraclitellian,’ through the shifting forward of the 
generative pores on to the 17th segment. 
Ovaries and Oviducts—I have been able to prove by dissection 
that the presence of two pairs of oviducts in consecutive segments is 
areality ; the two oviducts of each side were quite obvious and were 
each furnished with their own ovary. Moreoverin var. No. 11 there 
was an additional (third) ovary in segment 11, on the right-hand side. 
In var. No. 10 I also noted three pairs of ovaries. 
The occasional occurrence of more than a single pair of ovaries in 
this Earthworm lends additional support to my identification in 
Acanthodrilus of certain glandular structures with rudimentary 
ovaries, and also to Prof. Lankester’s description in Chetogaster of 
two pairs of ovaries, which has been recently doubted by Vejdovsky'*. 
In the present instance there can be no doubt of the presence 
occasionally of two or three pairs of ovaries, since they were extremely 
conspicuous on account of their large size, and contained abundant 
mature ova. 
In two varieties (No. 5) there were only a single pair of ovaries 
present, but with separate openings on to the exterior. I have 
already in the present paper (p. 301, note) referred to the fact that this 
variation also occurs in Megascolex. 
Spermathece.—The number and position of the spermathece have 
been so constantly made use of as a systematic character, that it is 
well to emphasize their variations in the present species. They vary 
from two to four pairs, and may be placed in any of segments 6-11. 
In most cases they get to be placed further forward when the male 
generative pores shift their positions forward, but this relation is by 
no means constant. The occasional symmetry of these organs (e. g. 
in var. No. 12 and 13) cannot be a matter of any importance ; it was 
only observed in two of the four specimens. 
Male Generative Pores.—The position of these pores varies from 
segment 14-21, but they were invariably behind the female generative 
pores; there was particular relation between the positions of the 
male and female pores, except that the latter were always in front of 
the former. 
é * System u. Morph. d. Oligochexten, p. 145. 
Proc. Zoou. Soc.— 1886, No. XXI, 21 
