POLYZOA. 
65 
by having a notch in the lower margin of the orifice, (Fig. 14, Case A 2. 
Schizaporella unicornis). 
In many of the Escharina, the front wall of the cell is produced Case B l. 
into a stout process or macro at the lower margin of the orifice (genus 
Mitcronella), or, again, a collar or tube grows up round the primary 
Fig. 14. 
Schizoporella unicornis, magnified. 
Fig. 15. 
Retepora oeaniana. 
orifice, thus giving rise to a secondary orifice (Smittia, Porella, etc., 
Case B 1). 
In the Celleporidw (Case B 1) the cells are typically pitcher-shaped Caae B h 
and arranged vertically, and tend to be heaped up from overcrowding. 
Gell&pora pumwosa forms thick pumice-like masses composed of 
