PLATE XX. 



Fig. \.- Mycale acerata Kirkp. | nat. size, p. 36 ; a, surface (x 5) ; l, vertical section, nat. size. 

 Fie. 2. — Mycale magellanica (Eidley). Dermal reticulum showing the uniformly level surface, p. 36. 

 Fi«. 3. — Esperiopsis villosa (Carter). Nat. size, p. 3.5 ; a, b, villous and pilose surface (x 10) ; c, vertical 



section ( x 5). 

 Fm. 4. — Artemisina apolUnis (K. & D.). f nat. size, p. 34 ; a, villous process on the surface of the sponge 



(X 5) ; 6, surface (x 5) ; c, vertical section (X 5). 



