PLATE XVI. 



FIG. 



1. Flustra foliacea^ p. 115; nat. size. 

 1 «, 1 Z>. , zooecia magnified. 



2. Flustra papyracea, p. 118; nat. size. 



2 a. , zooecia and ovicells. 



3. Flustra securifrons, p. 120; nat. size. 



3 a. , zooecia, with avicularia and ovicells. 



4. Flustra carbasea, p. 123 ; nat. size. 



4 a. , zooecia. 



