GREY CHALK MARL. 107 



projection, which proceeds from the margin of the terminations, appears to 

 constitute its specific character. 



I have named this species in honour of Davies Gilbert, Esq. M. P. 

 V.P.E.S., &c. of Eastbourne, a gentleman universally respected for his 

 public talents, and beloved for the suavity of his manners, and the excel- 

 lence of his private character. 



Localities. In the cliff near Southerham, and Beachy Head. 



9. A flexuous zoophyte, occurring in masses of an oval form, from two 

 to five inches in length. 



These fossils bear some affinity to the preceding, but those in my pos- 

 session do not exhibit any traces of pores, or cells. They have been 

 supposed to belong to the genus Spongia, but more illustrative examples 

 are required to establish the conjecture. Their constituent substance is 

 calcareous spar. 



Localities. In the beds of marl that form a junction with the grey 

 sand, at Southbourne. 



10. Portions of a fohaceous zoophyte, allied to the genus Flustra, the 

 surface covered with small, ovate, symmetrical openings, disposed in 

 meshes. 



Localities. Stoneham, Middleham. 



ECHINITES. 



The echinites of the grey marl have their characters but imperfectly 

 defined, and are extricated from the surrounding matrix with great dif- 

 ficulty. Their crustaceous coverings are invariably converted into a 

 brittle crystallized carbonate of lime, and their cavities filled with marl ; 

 they are generally distorted by compression. 



11. Cidaris. Tab. xvii. fig. 1. 



Circular, depressed, with ten porous ambulacra, and as many areas. 

 The surface is covered with twenty rows of small, elegant, perforated 

 papillae, set on tubercular projections, the margins of which are cre- 

 nulated. 



This fossil appears to be a variety of Echinocidaris saaatilis. 



p 2 



