PLATE X. 



Receptaculites occidentals (page 45). 



Figaro 1. Receptaculites occilentalis. Upper view of a fragment of a large 

 specimen. At a, a rubbed portion exposes sections of the 

 cylindrical columns. 

 2. A more weathered specimen, upper side shewing the convex ends 

 of the columns. 



" 3. Cupped central part of a specimen. 



" 4, 5. Detached fragments reversed, the upper side downwards, shewing 

 the rhomboidal bases to the columns. 4a ditto., shewing the 

 connecting stolons. 46, the same magnified. 



" 6. One or two columns magnified, reversed, a, the rhomboidal gran- 

 ulated space ; b, the connecting basal stolons ; c, the apices of 

 the columns ; d, the interstices between them ; 6* is the base 

 of one of the columns, more highly magnified. 



" 7. Shews a portion of the lower surface polished. Some of the 

 rhomboidal spaces are connected by the stolons with each 

 other. 



Receptaculites australis (page 47). 



" 8. Receptaculites australis, Salter. A new Australian species, intro- 

 duced for comparison. Lower surface, with the lobed bases of 

 the columns. 



" 9. Some of the columns magnified. The stolons are not clearly seen 

 in this specimen. 



" 10. View from the inner surface of these lobed bases, shewing the 

 ramifications of the sarcode highly magnified. 



