336 FRANK E. BEDDARD. 
longer than in Tubifex, therefore: the brown peritoneal cells 
commence in the 6th segment. There are septal glands 
present, which lie in Segments 4, 5, and 6. The intestine is 
attached to the parietes by muscular bands. 
§ Generative Organs. 
In worms not sexually mature, two pairs of gonads in 
an immature condition were to be seen (in longitudinal sec- 
tions) in Segments 10 and 11. I presume that these are the 
testes and ovaries, though there was no means of telling 
their nature from their structure. In another specimen which 
had advanced a little, but not much, further towards maturity 
the gonads were bigger, and stretched right across the seg- 
ment, and their nature (testis and ovary) could be established 
from their minute structure, but there was no trace of ducts or 
of spermathece. 
After examining five or six specimens of Branchiura 
which were sexually immature, I was so fortunate as to dis- 
cover a single specimen with fully developed sexual organs. 
This individual was very much longer than the others, the 
relative size being shown in the figure (fig. 1, a, B). It was 
an inch and a half to two inches in length. ‘The presence of 
the sexual organs gave a milky-white appearance to some of 
the anterior segments. This was chiefly owing to the sperm- 
sacs, 
With regard to the external differences produced by the 
development of the sexual organs I may direct attention to 
fig. 8. The clitellum occupies three segments (10 to 12). 
The epidermis covering this region of the body is deeper than 
elsewhere, but still, as in aquatic Oligocheta, consists of one 
layer of cells only. 
On to the 10th segment open the spermathece. The 
paired apertures are situated behind the ventral seta bundles, 
The atrial pores are upon Segment 11. They correspond 
in position to the spermathecal pores, but lie where the ventral 
sete would be were these present. The ventral sete of Seg- 
