MM. Kowalevsky and Barrois on Anchinia. 13 
peared, and nothing remains of it except a dilatation of the 
corresponding region, a dilatation, however, which disappears 
in the adult to produce a slender and perfectly uniform tube. 
Lastly, at the base of the stomach we notice the slender tube 
which represents the ramified gland of the Ascidia. 
The vibratile band is now very distinctly formed; and it 
can easily be traced throughout its whole extent up to the 
spiral organ, which is already present. 
The genital masses have decidedly given place to a defini- 
tively separated testis and ovary, the former composed of 
rounded cells and the latter of a follicle containing several 
ova; both cf them open by a common aperture into the night 
lateral expansion of the cloaca. 
Lastly, the disseminated cells have lost all connexion with 
the genital organs ; they are now arranged in groups of four 
or five around the digestive tube. 
6. In the adult the branchial clefts have increased very 
perceptibly ; the peduncle has attained a vertical position and 
come to be placed in the immediate vicinity of the heart ; it 
is much less apparent than in the preceding stage; and the 
whole animal has acquired the definitive form of the figure 8. 
The cells of the kidney are no longer collected into groups as 
previously, but form a network around the digestive tube. 
The testis presents a deferent canal; and its glandular portion 
has become elongated and ramified around the stomach, 
which it partly conceals. Finally, the tunic has become 
much thickened; and spots of red pigment have made their 
appearance in the middle of the body and above the apertures. 
Ill. Affinities. 
We have already put forward some considerations upon the 
central position, between the two great extreme groups of 
the Salpz and Ascidia, and especially between Doliolum and 
Pyrosoma, that is occupied by Anchinia trom the point 
of view of the arrangement of the great cavities. But these 
general relations give us but little information as to the 
precise affinities of this interesting type and the exact place 
which ought to be assigned to it from the complete know- 
ledge of its organization. 
lf we endeavour to compare the preceding description with 
what we know of the other Tunicata, we find that, as regards 
the structure of the adult as well as the position of the buds 
upon the stolon, Anchinia presents a great resemblance to 
Doliolum. 
As regards the organization of the adult form, we see that 
