121 
Bryozoa of the Bay of Naples. 
men, and does not give all tlie characters quite correctly. 
The mouth is not circular, and has no thickened and raised 
margin, though when the zooecial case dries and contracts in 
the centre it gives this appearance to the aperture. The distal 
edge is rounded, the proximal nearly straight. Just above the 
aperture arc from two to four small projections on the zooecium ; 
the tubular processes have a septum in the middle. From 
the back of each cell grows a long radicular tube (h)- and in my 
specimens, which were attached to sponge, there was a “grap- 
pling-hook ” (p) at the end. The position of these roots is 
shown in Busk’s figure 2 by the circles, which he does not 
mention. 
In the small piece drawn there are two avicularia to each 
of the centre cells, while the others have one on the right 
and left respectively. In larger pieces there are several lines 
of double avicularia; but this is subject to some variation. 
The piece drawn shows the life-history of the Bryozoa in a 
very complete manner ; and as the walls are transparent, it is a 
very good species for examination. First at k are the pro¬ 
cesses, which gradually increase and coalesce as at m and l ; 
this grows until an enclosed zooecium as at a is the result, 
when the polypide begins to bud inside a. This grows 
through h , c, d stages, until at e the polypide is perfect; at c 
and d the oral opening of the zooecium is formed. At f there 
is a polypide budding in an older zooecium; but at g in the 
same cell is seen a “ dark body,” which is really the remains 
of a previous polypide; for after a time each polypide loses 
vitality and gradually becomes reduced to this “ dark body,” 
when another polypide buds from the side. 
Loc. Living: Straits of Magellan, New Zealand (Busk), 
Adriatic (Heller) ; Naples, 30-50 fathoms. 
51. Membranipora pilosa, Pall. 
European seas generally, common. From Australia I have 
this, if M. verticillata , Lamx., is to be considered syno¬ 
nymous. 
52. Membranipora membranacea , L. 
European seas. 
53. Membranipora Rosselii , Aud. 
The calcareous perforated expansion is somewhat smaller 
than figured by Busk ; and if Manzoni’s specimen (Bry. Foss. 
Ital. 4 a contr. pi. iii. fig. 15) is really Rosselii, it would seem 
to be very variable, as the open space there is but little larger 
