40 DR J. STEPHENSON ON 
the outer setee of a bundle are longer than the inner, each bundle forming a gradated 
series; thus the lengths of the sete of a bundle of five in segment x. were, from the 
outer to the inner side, 106, 101, 97, 90, 81 ~; in another bundle the lengths were 104, 
i 
Fie. 4.—A setal bundle of Lwmbricillus subterraneus. 
100, 94, 90, 83 4. The longest sete are thus rather more than ‘1 mm. in length; 
in thickness they are about 5-6 u. The ante-clitellial of both dorsal and ventral series 
are on the average rather longer than the post-clitellial. 
The pharynx occupies segments ii.-iil. The esophagus begins to be covered with 
chloragogen cells in vi.; it presents no dilatations or diverticula, and passes into the 
intestine about segment xvi.; this latter portion of the alimentary canal is bulged 
interseptally and constricted at the septa. Septal glands (Pl. I. fig. 3) are present in 
segments iv., v., and vi.; those of each side are, as usual, longitudinally connected ; the 
glands in iv. are small, in v. are spread out on the septum (2), and in vi. are large, 
lying mainly longitudinally in the segment. 
The dorsal vessel varies somewhat in its place of origin; this may be from the 
thirteenth to the seventeenth segment; it bifurcates in the prostomium. There are 
four lateral commissures on each side ; the first of these arises dorsally in the posterior 
part of segment ili. and runs forwards into i1., or even i.; the second arises dorsally in 
the anterior part of iv., and runs forwards into iii.; the third belongs altogether to 
iv., and the fourth tov. The ventral vessel bifurcates anteriorly in iv. ; it exists as a 
definite vessel as far back as the anus, being frequently separated from the intestine, so 
that a “‘ window” intervenes between the two. The appearance of the ‘sinus’ in the 
alimentary wall when the posterior part of the body was much engorged, the animal 
dying and the blood coagulating, was that of a thick, close-set network of large vessels, 
with hardly any interspaces between them. The blood is red. 
The nephridia begin in segment vii. ; each is an ovoid mass, with a very small 
ante-septal portion; there is a slight brown pigmentation in the anterior part of the 
post-septal. The tube is loosely coiled within the mass; the duct leads forwards from 
its lower surface in front of its posterior end, and is much shorter than the body of the 
nephridium. The calomic corpuscles are irregularly pear-shaped or oval granular 
nucleated cells. There are also to be seen in the body-cavity a number of smaller 
spherical refractile bodies, 
