4 



BRITISH FOSSILS. 



Marl. It is a very remarkable stratum, abounding in peculiar fossils, 

 and containing numerous echinoderras. I have examined it and found 

 the small variety of Galerites castanea plentifully near the village of 

 Chaldon, in Dorsetshire. Mr. Morris and Captain Ibbetson have col- 

 lected it in a corresponding geological position in several localities of the 

 same county. Both larger and smaller varieties occur near Warminster. 



Foreign Distribution. — In Savoy and in Normandy, apparently 

 always in the same geological horizon as in England. 



Description of the Plate. 



Figs. 1, 2, 3, 4. Various positions of a perfect example from Dorsetshire of the tumid 

 form of var. Minor. 

 Fig. 5. Internal cast. 



Fig. 6. Ambulacral and interambulacral plates and their sculpture, taken from the 

 centre of the sides. 



Fig. 7. Arrangement of the pairs of pores in the neighbourhood of the mouth. 

 Fig. 8. Diagram showing the relative position of the pores and avenues. 

 Fig. 9. Anus. 



Fig. 10. Primary tubercle and granules, highly magnified. 



June, 1850. 



Edward Forbes. 



