PLATE x\an. 



1 . — A rough spongelike-looking ball with, strong spines. 



2. — Spongolithis (?) a spicule. 



3. — A state of a Haliomma — strong spokes from central nucleus to 

 circumference, at imequal distances — some network apparently 

 spimiing partly over one side, according to MiiUer's description. 



4. — Spongolithis anchor a of Ehrenberg — A spicule. 



5. — Spongolithis ramosa, Ehr. 



6. — Serpent-like form — very frequent and variaOle in the Barbados deposit. 



"7. — Lithasteriscus reniformis. Ehr., '■'■Nord and Stid Amerika" Taf. 

 VI. fig. 35. / think all these bean-like forms are wartedor rough- 

 ened on the surface, not truly foraminated. 



8. — An irregular three-lobed transparent Plate from Chimborazo, Bar- 

 bados, analogous to fig. 6 on PL VII. Dr. Wallich says these 

 are parts of an organism constituting a new genus intermediate 

 between Sponges and Polycystins ; this plate, forming part of 

 the outer siliceous skeleton, the interior being filled with free 

 spicules. The ovals, Nos. 1 and 2, on Pi. 7, (of whicli many 

 more examples have since been found) are plates instead of 

 spicules, taking the place of an internal skeleton of a kind of 

 organism of which no perfect specimen has yet been found; and 

 which is also iutemiediate between Sponges and Polycystins. 



9. — Spongolithis aspera. 



