PLATE XVII 



PAGE 



Figs. 1-4. HINDIA SPH^ROIDALIS Duncan 195 



1. Exterior view. 



2. Radial section of sponge. 



3. Tangential section showing tubes. X 4. 



4. Radial section showing spicules and tubes. X 4. 



Helderberg formation, Keyser member, Cash Valley. 



Figs. 5-9. STREPTELASMA STKICTUM Hall 198 



5. 6. Lateral and posterior views of corallum. 



7. Transverse section. 



New Scotland formation, New York. 



8. Interior of calyx. 



9. Transverse section of corallum. 



Helderberg formation, New Scotland member, Cherry Run. 

 W. Va. 



