or Little Known, Polyzoa. 195 



EXPLANATION OF PLATES. 



Plate I. 



Fig. 1. Schizoporella Ridleyi, young cells. Fig. la. Older group, 

 showing the converging grooves and ovicells. 



Fig. 2. Porella marsupium. Fig. 2a. Young cell. 



Fig. 3. Cribrillina setirostris. 



Fig. 4. Schizoporella arachnoides. 



Fig. 5. Membranipora serrata. Two of the cells, showing the 

 condition described as M. acifera. 



Plate II. 



Fig. G. Lehythopora hystrix, natural size. Fig. 6a. Outline of 

 portion magnified. Fig. 6b. Two cells showing roughened 

 and pitted surface, membranous covering of ovicell, oral and 

 separate large avicularia. Fig. 6c. Part of peristome, show- 

 ing avicularium and spiral tube. Fig. 6d. Profile of cell to 

 show situation and projection of ovicell. 



Fig. 7. Gellepora exigua, showing oral avicularia and ovicells. 

 Fig. la. Young cells from growing margin. Fig. lb. Por- 

 tion of older colony, showing scattered avicularia. 



Fig. S. Rhynchopora profunda. Cells from growing margin, show- 

 ing the commencement of the calcareous growth. Fig. 8a. 

 More advanced stage of this growth. Fig. 86. Two cells 

 with calcareous overgrowth, showing scattered avicularia and 

 commencing development of ovicells. 



p2 



