Fig. 8-1. A common marine sponge (S/con) which is 

 about 1 inch long. The individuals grow in clusters 

 and are very commonly found clinging to debris in 

 the ocean. 



A B 



Fig. 8-2. Two deep-sea sponges. Their skeletons are com- 

 posed of siliceous (glass) spicules. A. Venus' flower 

 basket (Euplectella). 6. The glass rope sponge (Hya- 

 lonema). 



Fig. 8-3. A fresh-water sponge collected in a Michigan stream; it measures about 14 inches long and is a green- 

 gray In color due to the presence of unicellular algae growing in the body cells. 



