^#fe"^v. 



CHARACTERISTIC DEEP-SEA TYPES. SPONGES. 179 



form : a thick, coarse, smooth sheet, with stout branches, either 

 round or angidar. 



One of the most abundant sponges 

 is the small liadiella sol (Fig. 545), vN\i\,^\iJ!,i 



which extends to over 1,000 fathoms 

 in depth. Its general appearance is that <;;c/j^' 

 of a segment of a sphere surrounded by 

 a fringe of needles, with a layer of larger 

 needles radiating from the centre of 

 the disk and forming the base. pi^. 545. - Radieiia sol. 





