164 



Fig. 16. Calcareous deposits and calcareous ring of Synaptula aspera 1-3, Synap- 

 tula recta 4-6 and Synaptula striata 7-9. 1-2, 6 & 8 x 180; 3-4 & 7 X 24; 

 5 & 9 x 1000. 



