PLATE XXX. 



PAGE 



Fig. 1. Desmacidon frnticosa, vav.: natural .size, . . . .104 



Fig. 2. Myxilla nohilis (Btation 320) : natural size, . . . .140 



Fig. 2rt. Portion of .^uiftice, eDlarged, showing pore-areas : x d. 



Fig. 3. Myxilla paucispinata, witli ]iatclie,s (p) of Esperiopsis pvlchella growing 



on it ; natural size. . . . . . .132 



Fisf. 4. Phimohalichondria mammillata ; natural size. . . . .156 



Fig. 4a. Surface section, showing the pores; x 150. 



