A NEW BRANCHIATE OLIGOCHATE. 335 
the 8th segment (fig. 9, H’.), and connect the supra-cesophageal 
with the ventral blood-vessel. They appear not to be con- 
tractile, and coexist in the 8th segment with the usual pair of 
contractile hearts. In each segment of the body in this region 
there is, as has been mentioned, a pair of vessels given off from 
the supra-intestinal trunk at about the middle of the segment, 
which join the integumental network. In the 8th segment a 
corresponding pair of vessels are present, which arise from the 
intestinal hearts. 
‘The existence not only of a supra-intestinal vessel, but of 
intestinal hearts connecting it with the ventral vessel, was un- 
known among the Limicole until the publication of Stole’s 
important work upon the Bohemian Tubificide. Such hearts 
exist in the genera Bothrioneuron and Lophocheta. I 
have also described an “intestinal” heart in the remarkable 
fresh-water Oligochete Phreodrilus,! which appears to be 
the representative of a distinct family, though showing some 
points of resemblance to the Tubificide. 
§ Nephridia, Alimentary Tract, &e. 
The perivisceral cavity appears to contain no free cor- 
puscles. The anterior septa are thicker than the following ones. 
The nephridia are constructed on the same plan as in 
Tubifex. The first pair were in the 12th segment. The 
nephridium communicates with the exterior by a pear-shaped 
vesicle (see fig. 14), dilated where it receives the excretory 
tubule and gradually narrowing towards the external orifice, 
which is very small and placed in front of the ventral seta 
bundle, at a point corresponding to about the middle of each 
bundle. 
The alimentary tract is like that of Tubifex. The 
buccal cavity alone is not ciliated; the rest of the tube lying 
behind the buccal cavity is ciliated. 
The esophagus only differs from the intestine, which com- 
mences in the 11th segment, by its smaller calibre ; it is much 
1 «On Two New Genera of Aquatic Oligocheta,” ‘Trans, Roy. Soc. Edin.,’ 
vol. xxxvi, 
