PLATE VIIL 

 " ISODICTYA FERULA, Bowerbank. 



Figs. 1 and 2. Represent the type-specimens of the 

 species. Natural size. 



Fig. 3. A skeleton spiculum. X 264 linear." 



" ISODICTYA CRASSA, BoiuerbanJc. 



Fig. 4. Represents the type-specimen. Natural 

 size. 



Fig. 5. A small portion of the dermal membrane, 

 exhibiting its reticulated structure. 



Fig. 6, A skeleton spiculuni." 



