PLATE X. 



CRETACEOUS SPECIES. 

 Fig. 



1 to 17. Rhynchonella plicatilis, oar. octoplicata, Sow. A series of specimens and 



varieties from the Chalk of Norwich. 

 IS to 20. ,, sulcata, Parkinson. Upper Green Sand of Cambridge. 



21, 22. 

 23 to 36. 

 37 to 40. 

 41, 42. 

 43 to 46. 

 47 to 49. 

 50 to 54. 



„ Speeton Clay, Yorkshire. 

 ,, Varieties and malformations, from Cambridge, 

 plicatilis, Sow. Chalk, Brighton. 

 Var. (Kent). 

 „ (var. Woodwardi, Dav.). 

 ? Chalk, Charing. 



Cuvieri, D' Orb. Lower Chalk. 



