PLATE III. 



Fig. 



1. Trigonia perlata, Ag. Coral Rag, Pickering; the rows of costse are fewer than is 



usual. (Page 22.) 



2. „ „ The same formation and locality; the largest specimen known. 



3. „ „ Young specimen from the same locality. 



4. 5 a, 5 b, 6. spinulosa, Y. and B. Inferior Oolite (Dogger), Blue Wyke, Yorkshire. 



(Page 44.) 



7. „ corallina, D'Orb. Coralline Oolite, Pickering. (Page 45.) 



8, 9, 11. „ Young specimens, Coral Rag, Steeple Ashton, Wilts. 



10, a. ,, Griesbachi, Lye. Cornbrash, Rushden, Northamptonshire ; natural size. 



(Page 34.) 



10, b. „ „ The same specimen magnified. 



