120 THE WORLD OF THE SEA. 
The Umébellularia, which are only found upon the shores of 
Greenland, and the Vizrgularia, of Lamarck, are Pennatulide. 
The Virgularia mirabilis is one of the most beautiful of marine 
polypes. Two series of half-moon shaped wings, obliquely hori- 
zontal, are placed symmetrically round an upright axis; they 
embrace the stem, clasping it alternately like two broad ribbons 
UMBELLULARIA. VIRGULARIA. 
rolled round a stem in an inverse direction, thus producing the 
effect of two flights of stairs winding round opposite ways. The 
wings are wavy, deeply dentated, and of a bright yellow. These 
dentations are the homes of the polypes, which show occasionally 
their gaping mouths and their spread tentacles. These polypes 
are whitish, semi-transparent, and form a fringe of small dia- 
phanous white stars. 
