255 
part of the oesophagus is separated from the other. In the 
specimen from Lynæs this peculiarity was rather more conspicuous 
than in that figured by de Man. 
Cylindrolaimus tristis n. sp. 
Pl. DI. 'figs. 21, 23, 26. 
The only species of this genus which was collected here agrees 
with none of the species described by de Man. I have taken it in 
the Furesø for two years successively in the same locality, namely 
between Hjortholm and the biological laboratory. It occurs on roots 
of plants in the edge of the water. Its movements are exceedingly 
Characteristic: It does not swim but it moves very slowly with the 
most awful writhings, bending its body extraordinarily abruptly at 
aå single or more spots as if intending to break it to pieces; at 
the same time the animal is trembling as if very miserable 
and piteous. I suppose these movements are. peculiar for the 
genus partly because de Man has named one of his two species 
C. melancholicus; it would be just as suitable for the species from 
the Furesø; I consequently named this species C. tristis. 
The species from the Furesø is considerably larger than the 
two known from Holland; while the larger of these is a little more 
than one milimeter long the Danish species measures almost two. 
But it is relatively much more slender. The body is tapering 
slightly forwards with a rounded head devoid of lips. I have not 
been able to state if setæ are present, at any rate they are 
exceedingly small and inconspicuous. The lateral organ placed near 
the head is of a shape diverging from that known in the species 
from Holland; in profile it has the shape of a narrow funnel 
running obliquely inwards in the body, forming an angle of 
nearly 45? with the long axis of the former. It is not to be 
Seen in my figure which was drawn after a specimen prepared 
Where it was not visible, I have only seen it on living animals 
and always rather indistinctly. The oesophagus is long and increases 
towards its proximal end. Its Chitin-intima, as also observed by 
