PLATE LXIX. 



FIG. 



1. ALCYONIDIUM HIBSUTUM, p. 360. Of the natural size. 



2. A portion of the surface magnified. 



3. The dried crust of HYDRACTINIA ECHINATA, p. 34, invest- 



ing a shell of Buccinum undatum. 



4. A small piece of this crust magnified. 



5. CLIONA CELATA of Grant, with (6) its siliceous spicula. 



See my History of British Sponges and Lithophytes, 

 p. 125. 



