EXPLANATION OF PLATE V. 



Fig, I, Spongitta alba, Carter. 



A thick section through the. base of a branch in the neighbourhood of an 

 osculum, x io. 



The soft parts of the sponge have been entirely removed ; the filmy substance shown particularly in 

 the lower lobes of the section is the subsidiary skeleton. 



Figs, 2 t 3, 3a, Laxosuberites lacustris, sp. nov. 



2. Dried specimen on a stone, somewhat enlarged. 



3. Mass of gemmules removed from a rock by the wind, seen from above and 

 considerably enlarged. 



3«. Part of the same specimen, seen from below. 



Fig, 4. Tetilla dactyloidea (Carter) var. lingua, nov. 

 Two of the type specimens, nat. size. 



The figures on this plate are reproductions of direct photographs. 



