114 
SUPPLEMENT 
upper part of the back on each side is a series of pores very 
symmetrically placed : it is from those orifices that the hu- 
mour which invests the body of the lumbrici comes forth. 
Some authors think that at the same time they are sorts of 
stigmata for respiration. 
The general envelope of the lumbrici is eminently con- 
tractile, in consequence of the thickness of the muscular 
stratum, which doubles it. As for the skin itself, it presents 
this character of irritation which is found in all the animals of 
the class. The skin is more slender, and softer in the intervals 
of the rings, but these latter are more inflated and more re- 
sisting. Each of them is provided, to the right and left, 
with a number, variable, as it would appear, according to 
the species, of small calcareo-corneous setas, of a golden 
yellow, disposed in pairs ; one latero-superior, and the other 
latero -inferior, and the succession of which, on each ring, 
forms four longitudinal series on each side of the animal, or 
eight in all. These setae, rough and resistent, are more or 
less short, and strongly directed backwards. This is what the 
appendages become reduced to in this genus of animals. 
There is, in fact, no trace of tentacular parts, not even around 
the mouth. The intestinal canal is simple, extending from 
the mouth to the anus. The former is very small, for it is 
pierced in the first ring, which is remarkably pointed ; but 
as it opens a little obliquely at its inferior part, there result 
two kinds of lips, the upper of which is oval and much longer 
than the other, which really possesses but little sensibility. 
There is not, at the anterior part of the canal, any buccal 
dilatation, or teeth, or lingual enlargement. The oesophagus, 
when arrived to about the sixteenth ring, terminates in a 
true gizzard, almost as thick as a pea, of a fleshy and ten- 
dinous tissue, with fibres a little oblique. All the rest of the 
intestine goes directly without enlargement to the anus, which 
is pierced in the form of a longitudinal cleft in the last ring. 
13 
