[dwvhon] 



FOSSIL SPONOKS 



Trank. IH'.Kl. 8kc. IV.— Piath I. 



Fic. 1. 



Fui. :t. 



Ki(i. 2. 



Fi(i. 4. 



Fig. \ . — Protos'pongia fftrniiniid. 



Fig. l.—P. monorurnn. 



Fig. 3.— Do Showing osculuiii, partly broken away. 



Fig. 4.— P. tetranema. Seen in section with root. (All natural size.) 



123 



M 



