PLATE VIII. 



PAGE 



Fragments and spicules of Tiegeria pulchra, F. E. S., .. . 94 



Fig. 1. Outside view, from the upper part of sponge ; x 100. 



Fig. 2. From lower part of sponge, outside ; x 100. 



Fig. 3. Floricome, from the upper part ; x 500. 



Fig. 4. Discohexaster from the parenchyma of the side wall ; x 500. 



Fig. 5. Fragment of a graphiohexaster from the parenchyma near the outer surface 

 of the side wall ; x 500. 



Fig. 6. Section through the entire thickness of the sponge, showing the arrange- 

 ment of the connected and loose spicules ; x 175. 



Fig. 7. From the lower part of sponge, inside ; x 100. 



This plate was arranged by Sir Wyville Thomson. 



