OCIROULATORY APPARATUS OF THE NEMERTBEA. 11 
continued even further backwards. But there are always some 
fibres between the proboscidian sheath and the intestine, even 
in the cesophageal region. 
The ganglia and the lateral nerves are always outside of the 
circular coat and within the basal membrane. 
The intestinal tract has no diverticula. The mouth is 
situated behind the ganglia. The proboscis has no stylet, the 
head no lateral furrows, the brain no posterior lobes. 
We shall see that the vascular system occurs in two forms. 
The first approaches that in Cephalotrix, the second that of 
V. Armandi. But this will hereafter be noticed. 
I will now sum up in a few words the characters of Valen- 
cinia (borrowed from the typical species longirostris of 
Quatrefages) to justify my first assertion that V. Armandi 
can in no case be placed in this genus. 
Within the basal membrane there are, through the whole 
length of the body, three muscular coats, viz. an outermost 
layer of longitudinal fibres, then a circular layer, and finally an 
innermost longitudinal one. There is no trace of an inner- 
most circular layer inclosing the proboscidian sheath and the 
intestine. 
The whole central nervous system lies between the circular 
muscular coat and the outer longitudinal one. 
The whole intestinal tract has, with the exception of the 
cesophagus, diverticula. The mouth is placed behind the 
ganglia. The proboscis has no stylet, the head no lateral 
longitudinal furrows. But posterior lobes are present, even 
large, and are directly continuous with the brain. 
When describing the vascular system we shall see how extra- 
ordinarily that of Valencinia deviates from that of Cari- 
nella, Cephalotrix, and the new genus Carinoma. And 
whoever chooses to form an opinion on this point ueed only 
compare the figures 1 (Cephalotrix), 2 and 4 (Carinella), 
5 (Carinoma), with 13—16 (Valencinia). 
In none of the four genera can any point of special import- 
ance be derived from the proboscidian sheath and proboscis. 
In the one the proboscidian sheath is long, in the other (Cari- 
