DESCRIPTION OF THE PLATES. 
PLATE II. 
Fig. 1. Clypeus sinuatus ofLeske, from Oxfordshire. 
2. Ecliinanihites 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 ofLeske. 
8. A cast of Echinanthus humilis from Malta. 
9. Part of the cast of a galeated echinite. 
10. Conulus albogalerus ofLeske, from the Kentish chalk-pits. 
11. The under part of the same fossil. 
PLATE III. 
Fig. L Echinites saxatilis, with its spines, imbedded in flint. 
2. Echinodiscus subrotundus from Italy. 
3. Spatangites ovalis. 
4. The upper surface of Spatangus radiatus from Maestricht. 
5. The under part of the same fossil. 
6. Echinites pyriformis. 
7. Echinites lapis cancri. 
8. Spatangites brissoides ovalis. 
9. Spatangus purpureas from Malta. 
10. Echinodiscus laganum from Verona. 
11. Spatangus cor marinum from Kent. 
12. Spatangus lacunosus from Malta. 
