PLATE XXI. 



no. 



1. Membranipora FlemingiIj p. 1G2; from a fully 

 developed specimen. 



I a,l 0. , young zooecia with the full com- 

 plement of spines ; avicularia partially developed. 



2, 3. , var., showing the produced portions 



of the cell below. 



4. Membranipora cornigera, p. 164. See Plate 

 XXII. fig. 4. 



5, 6. Membranipora aurita, p. 159. 



7. Setosella vulneratA; p. 181. 



