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mouth. This is then done in the way that the furrow extends 
further upwards along each side of the animal; the lips coalesce 
along their edge so as to form a closed channel, opening towards 
the exterior at its outer end and remaining in open connection 
with the ventral furrow in the bottom of which the mouth lies. 
Gradually the walls of the channel grow upwards, carrying along 
with them the tentacle sheath, and thus by and by the towerlike 
funnel is formed. 
It should further be added that the costæ disappear completely 
as soon as the young animal has attached itself; evidently it is 
then fixed for life, tliough it may perhaps be able to move 
sligktly along the surface of the body to which it has attached 
itself. 
The full report of this remarkable Ctenophore will appear in 
the Report on the Ctenophora of the Danish Ingolf-Expedition 
(Vol. V Part II), presumably in the course of next year (1911). In 
this preliminary notice I cannot enter on a more full account of 
the minor anatomical and embryological details of the animal. 
Regarding its affinities, it appears to be nearest related to 
Ctenoplana. Apart from the interest which the existence of a new 
type of such remarkably transformed Ctenophora affords, quite 
unusual importance must be ascribed to this new form, partly 
as it is the first viviparous Ctenophore known, but especially 
because the faet of the young being typical Cydippids seems to 
prove definitely that the creeping Ctenophores are really the most 
specialized of all Ctenophores, not the most primitive of them all. 
This faet decidedly speaks against theory of the derivation of 
both Ctenophores and Polyclads from forms like Ctenoplana and 
Coeloplana. 
The animal, which I name Tjalfiella, according to the wishes 
of Mr. Ad. S. Jensen, after the ship on which it was first 
observed, may be preliminarily diagnosed as follows: 
Sessile; the body laterally compressed, with no traces of costæ. 
The tentacles unbranehed. A ventral furrow prolonged at each 
