6 Dr. Augusta Ärnbåck-Christie-Linde. 
vasa efferentia embrace the proximal part of the ovary and 
unite in forming a common vas deferens, which lies on the 
inner free surface of the ovary and ends close to the orifice 
of the oviduct. Both the oviduct and the vas deferens open 
at the end of the gonad near each other. 
On the inner side of the mantle a large number of 
endocarps are visible. 
Remarks. 
In comparing Styela theeli with other Styelids, it appears 
that, while it agrees in some external and internal features 
with the members of the group Goniocarpa, it is distinctly 
marked off from other species. No Styelid that has been 
described has gonads which agree with those of Styela theeli, 
nor a dorsal tubercle which resembles the corresponding organ 
in the latter; even the alimentary canal is unlike that of other 
species. In some respects Styela theeli resembles in appearance 
Styela loveni: The leathery test, the expanded base and the 
depressed form are characters which remind one of Styela 
loveni. And as to the internal anatomy, it should be observed 
that the structure of the gonads offers several points of agree- — 
ment with the last-mentioned species. In both, the ovary 
is a sinuously curved tube of considerable length and 
with the same characteristic bend, the testis and the vas 
deferens show the same general plan of arrangement and 
structure. The situation of the orifices of the gonads which 
in both species are directed towards the atrial aperture, is 
also the same. | | 
There exist, however, more essential differences. With 
regard to the external aspect I would point out that Styela 
theeli is of greater size, that it is attached by the 
left side, and that the apertures are not so wide apart. 
It also differs in the condition of the test: the wrinkles and 
the arrangement of the folds around the apertures are dissimilar. 
With respect to the internal structure, there are several 
important differences. If we compare the gonads of the two 
species, it will be evident that, while agreeing in some general 
features, they differ in form and size, in the inflated oviducts 
and above all in the number, a character which is consi- 
dered to be of great value in distinguishing the different groups 
