20 
D. C. Danielssen. 
[No. i. 
The integument with its epithelium, nematocysts, mucous glands, 
and connective-tissue; the tentacular form, septal, formation, repro- 
ductive organs and nervous system, are all in perfect harmony with 
the Coelenterata type; but the feature which is established as the 
chief characteristic of that type viz. the gastrovascular cavity, is 
awanting, or is, here, transformed into a real body-cavity (Coelome); 
whilst at same time there is a fully developed intestinal canal with 
its origin at the mouth, and terminating in an anus, which in 
Fenja mirdbilis, does not directly communicate with the body-cavity, 
which is dividcd by 12 perfect septa into 12 longitudinal chambers. 
In the genus Ægir there are, at the extremity of the rectum 
a few millimetres in front of the anus, 12 minute, scarcely a milli- 
metre long, fissures by which the chambers of the body-cavity are 
placed in direct communication with the intestinal canal. Here 
therefore, we have a relation which, also, in respect of the digestive 
apparatus approaches somewhat to that of the Coelenterata, especially 
to that of the Ctenophora that, as is well known, has a long gullet- 
tube extending through almost the whole length of the body, and 
opening into the lateral gastrovascular space by two narrow lateral 
fissures. But what, however, marks an important difference, is the 
circumstance that, in Ægir, there is a perfectly developed intestine 
which opens into a real anus independent of the body-cavity; whilst 
in Ctenophora the gullet-tube opens into the gastrovascular space. 
The intestinal apparatus of the genus Fenja is, on the other hand, 
quite shut off from the body-cavity and therefore distinguishes 
itself more from the Coelenterata than Ægir does. 
If we make the Coelome the decisive feature, it becomes then evident 
that my two species must be removed from the ranks of the Coel- 
enterata; but where they should then be placed, I can really not 
determine. It may, however, be the case, that too much stress has 
been laid on the so-called gastrovascular apparatus, as a systematic 
feature, in naming the whole af the animal group that Cuvier called 
Zoophytes, Coelenterata. What is called gullet-tube in Actinidæ is 
possibly a rudimentary intestinal formation, and those at the sides 
of the adjoining chambers may perhaps be considered as a rudiment- 
ary formation of the coelome. This is still more distinct in the 
Ctenophora, where the gullet-tube not only has the form of an 
intestine, but also the function of a real digestive canal, even though 
anus is awanting, and is placed in direct communication with the 
gastrovascular cavity. In any case there is. here, in reality, no 
great distance from a complete separation between the intestine 
