DESCRIPTION OF THE PLATES, 



PLATE II. 



Fig. 1. Clypeus sinuatus of Leske, from Oxfordshire. 



2. Echinanthites orbicularis of Leske. 



3. Echinites vulgaris of Leske, from Sussex. 



4. Echinocorys scutatus of Leske, from Kent. 



5. Echinanthus ovatus from Verona. 



6. Echinodiscus bisperforatus from Verona. 



7. Discoides subuculus of Leske. 



8. A cast of Echinanthus humilis from Malta. 



9. Part of the cast of a galeated echinite. 



10. Conulus albogalerus of Leske, from the Kentish chalk-pits. 



11. The under part of the same fossil. 



PLATE III. 



Fig. 1. Echinites saxatilis, with its spines imbedded in flint. 



2. Echinodiscus subrotundus from Italy. 



3. Spatangites ovalis. 



4. The upper surface of Spatangus radiatiis from Maestricht. 



5. The under part of the same fossil. 



6. Echinites pyriformis. 



7. Echinites lapis cancri. 



8. Spatangites brissoides ovalis. 



9. Spatangus purpureus from Malta. 



1 0. Echinodiscus laganum from Verona. 



11. Spatangus cor marinum from Kent. 



12. Spatangus lacunosus from Malta, 



