CORALLINES. 
145 
produce the effect of two op- 
posing flights of stairs. These 
wings are waving, vandyked, 
and fringed on their outer 
edge, and of a brilliant yel- 
low ; the dentature of the 
fringe being the lodging of 
their pretty little polypes, 
which display occasionally 
their gaping mouths and ex- 
panded gills. The polypes 
are white and semi-transpa- 
rent. When they display 
their rays, the margin of 
Fig. 63. Brunch of V trgularln , 
enlarged. 
each wing presents an edging 
of silvery stars. 
The Umhellularia have a 
very long stem, supported by 
a bone (Fig. 64) of the same 
length, and terminated at the 
summit only by a cluster of 
polypes. They have been 
found in the Greenland and 
other northern seas. 
The Veretillum, which in- 
habit the Mediterranean (Fig. 
65), have a simple cylindrical 
body, without branchiae, and 
