18 
GUIDE TO THE CORAL GALLERY. 
High Wall 
Case 
E. end of 
^Gallery. 
as to give a reddish colour to the surface of the sea in daytime. In 
the Persian Gulf, a richly pigmented variety occasionally forms on 
the surface of the sea brilliant scarlet bands, which extend for many 
miles, 
Ciliata. 
The members of this group are characterised by the presence of 
cilia on the surface of the body. These organs may form a spiral coil 
round the anterior end of the body in relation to the mouth, or they 
may be distributed over the whole or part of the surface of the body. 
Carchesium 'polypinum (Plate XII. in the Case), which belongs to the 
group of “ Bell Animalcules,” occurs in ponds in the form of bluish 
Fig. 14. 
Stentor polymorphus, the Trumpet Polypus. (Magnified.) 
mucilaginous filmy patches on fresh-water plants, pieces of wood, &c. 
The branching fan-shaped colony is highly contractile, and shrinks 
into a spherical ball on being alarmed. Each individual has a 
bell-shaped body seated on a stalk. The cilia, which form a 
spiral fringe round the anterior end, set up a vortex in which food 
particles are carried through the funnel-like mouth and gullet 
situated inside the rim, and thence into the interior of the body. 
Vorticellci nebulifera (Fig. 13) also forms colonies ; the figure shows 
the individuals in various phases of contraction. Some species of 
Bell Animalcules are solitary and do not form colonies. Stentor 
