60 SHELL GALLERY. 
Case A. (^S* *9, one of the treasures of the " Challenger " Expedition, was 
Upright dredged from 1525 fathoms off Cape St. Vincent. The stem, which 
part * tapers gradually upwards, rises from a tuft of root fibres. The cup 
is formed of slender branches supported at the base by a delicate 
membrane. The branches are composed of biserial rows of cells 
(Fig. 9) opening towards the interior of the cup. The avicularia are 
Fig. 9. 
Case A 1. 
Kinetosldas cyathus. A branch magnified. 
a, an avicularium. (After Busk.) 
pear-shaped and pedunclate. Probably, in life, the cup is capable of 
being opened out to a considerable extent. Specimens of this species 
were also obtained from 21G0 fathoms in the South Atlantic. 
Scrupocellaria reptans, or the Creeping Coralline (Fig. 10 a, b) forms 
branching colonies, creeping over rocks and seaweeds, and attached 
by horny fibres often provided with curved hooks. The branches 
are composed of cells arranged in a double row. Each cell has the 
membranous area of its front surface protected by a branched flattened 
spine or operculum, and is produced and narrowed below ; at the 
upper outer margin is a minute triangular avicularium. At the base 
of the back surface is a small sack-shaped cell with a cleft at the 
upper end, in which a horny bristle is articulated. The little cell 
is termed a vibracular cell, and the bristle a vibraculum.* This 
* Vibraculum, a bristle. 
