4 



BRITISH FOSSIIiS, 



Dimensions of a well-formed example. 



Diameter . ♦ Oy| une, 



Height . . , , , 0^^5 , , 



Breadth of anal disk . a 



Breadth of an ambulacral area , , , . . 0^ , , 



Breadth of an interambulacral area , , . 0^ , , * 



Breadth of mouth 04 , , 



Locality and Geological Po^zY/ow,— Plentiful in the uppeh green- 

 8AND at Warminster, (Survey Collections.) 



Foreign Distribution.- — In the Craie chloritee of France, Bavaria, 

 and Minorca, and Hills-conglomerat of North Germany, 



Explanation of the Plate, 



Figs. 1, 2, and 3. Upper, under, and lateral views of a Warminster specimen. Fig. 4. 

 Genito-anal disk. Fig. 5. Two ambulacral areas, and one interambulacral greatly mag- 

 nified. Fig, 6. Arrangement of the pairs of pores near the mouth. Fig, 7. Ambulacral 

 plates and pores. Fig. 8. Relative arrangements of ambulacral and interambulacral 

 plates. Fig, 9. An interambulacral plate, with its tubercles. Fig. 10. A primary tubercle 

 seated on its pedicle, with the surrounding secondary tubercles, seen in profile. 



E, Forbes, 



Aprih 1849. 



