PLATE VII. 



CORALS FROM THE UPPEIl GREENSAND. 



Fig. 

 l."| Various shapes of the corallum of Siailotrochiis elongatus, Duncan. (P. 19.) The 

 3. y specimens are worn, and the coralUtes are in the form of casts. Small portions 



3. J of the original hard parts still remain. 



4. A transverse section of a corallum, slightly magnified. 



' ' \ The casts of the intercostal spaces simulating costae, slightly magnified. 



7. The corallum of ^Siwi/o/foc/^as G/?77«/afos, Duncan. (P. 20.) 



8. The transverse section, sUghtly magnified. (The specimens are in the form 



of casts.) 



9. The corallum of Wavia mimitissima, Duncan. (P. 22.) 



10. A portion, magnified. 



11. Endothecal structures of the corallum, magnified. 



12. The corallum of Smilotrochus Austeni, Edwards and Haime. (P. 19.) Copied 



from the ' Hist. Nat. des Coralliaires.' 



13. Tlie corallum of Thamnastraa superposita, Michelin, sp. (P. 22.) 



14.1 

 .' \ Specimens from the French Upper Greensand. 



16. A corallum, magnified. 



17. A calice, close to the edge of the corallum, magnified and drawn with the camera 



lucida. The continuous costai are to be observed inferiorly. 



