1g10.] J. STEPHENSON: Aquatic Oligocheta of the Punjab. 63 
Vascular system.—-The blood is yellowishred, and contains 
no corpuscles. The dorsal vessel contracts from behind forwards; 
it is incorporated with the wall of the intestine, and like the in- 
testine is covered by a layer of chloragogen cells. The ventral 
vessel is non-contractile, and is separate from the alimentary canal, 
with which it is connected in each segment by at least two vessels 
which pass into the wall of the latter. Besides branching vessels 
to the body-wall there are present in each segment a pair of lateral 
loops, which in the anterior part of the body extend into the gills 
(plate vii, fig. 3), the limbs of the loop forming the afferent and 
efferent vessels of these organs. The afferent vessel, springing 
from the dorsal vessel, is in this part of the body contractile ; 
further back, where the branchial processes are small, the lateral 
loops do not extend into them, and no part of the loops is con- 
tractile; the lateral loops exist, however, though much reduced in 
Fic. 3.—Region of approaching division in a specimen of Lahoria hortensis: 
showing portions of both anterior and posterior animals without gill-processes, 
and hence consisting of newly budded segments: A = anterior animal; B = poster- 
ior animal, 
size, back to the hinder end of the animal. In the first five seg- 
ments the lateral vessels do not present the appearance of regular 
loops, but form an extremely irregular and complicated plexus. 
The nephyidia begin by an open ciliated mouth; parts, at 
least, of the nephridial tube are also ciliated. I am not certain as 
to the segment in which they begin, my observations (which were 
a matter of some little difficulty, since these organs are not in 
this region very conspicuous) being discordant ; in one case the 
first nephridium seemed to be in segment ix, in another in xi, and 
again in Xiv, xv, xvi and xvii; it is possible that the position 
varies. They end some little distance in front of the posterior 
extremity of the animal; thus the last thirteen seta-bearing seg- 
ments may have none. They become smaller and smaller poster- 
iorly, appearing as small loops in contact with the ventral vessel 
and attached to the alimentary canal, somewhat as if they were 
budded out from the latter. 
