200 CATALOGUE OF THE MOLLUSCA 
and sometimes inside dead bivalve shells. It is then very tran- 
sparent and hyaline. MJodiola marmorata is occasionally found 
imbedded in the older individuals. This species may be the 
Ascidia prunum of Macgillivray but not of Miiller. 
3. A. virarngea, Mill. 
Ascidia opalina, Macg. Moll. Aberd. 312. 
Ascidia virginea, Forb. and Hanl. Brit. Moll. i. 33, t. O, f. 4. 
From the fishing boats at Cullercoats, rare. 
The hyaline transparency of the outer tunic, and the bright 
yellow and red markings of the inner, render this one of the 
most attractive of our Ascidie. The anal tube is much the 
longest ; an unusual circumstance in this family. 
4, A. vitrEA, Van Beneden ? 
Ascidia vitrea, Forb. and Hanl. Brit. Moll. i. 35. 
On small sea-weeds brought in by the trawl-boats from a few 
fathoms water.—J. A. 
We have not had the opportunity of seeing Professor Van Be- 
neden’s figures of Ascidia vitrea, but our specimens agree very 
well with the description of it in the “ History of British Mol- 
lusca,” with the addition that the inner tunic is spotted with 
yellow, and there is a yellow ring near the entrance to the bran- 
chial sac. We had at first thought that this might possibly be 
the young of the last, but it differs in being more ovate, and in 
having the anal aperture small and little prominent, as well as 
in the absence of red markings on the inner tunic. 
5. A. atprpa, Ald. and Hane. 
Body ovate, white, transparent, and slightly tuberculated ; 
attached laterally by a narrow base to small sea-weeds. Bran- 
chial aperture lateral or subterminal, large but not very promi- 
nent, the margin divided into eight points with intermediate 
red ocelli. Anal aperture a little distant from the other, and 
nearly half way down the body on the upper side ; largish, and 
little prominent, with six red ocelli. Outer tunic hyaline and 
colourless, covered with distant small tubercles. Inner tunic, 
transparent white with bluish lines on the upper part; below, 
opake white slightly spotted with yellow. There is a large 
opake white spot on the ganglionic prominence between the 
