74 GREEN OR CHLORITE SAND. 



margin. The appearance is too constant to be the result of accident, but 

 it is difficult to explain the cause of tliis deviation from the usual structure 

 of the shells of this genus. The specimens are from four to five inches 

 and a half wide, and weigh from one, to one and a half pounds. 



15. Mya, intermedia. Min. Conch, tab. 76. fig. 1. The casts are very 

 elegant, and correspond in every respect with the specimens of this species 

 that occur in the sandstone of Bognor : the impression of the hinge tooth 

 is very manifest. 



It is a circumstance worthy of remark, that this shell should have been 

 an inhabitant of the waters that deposited the green sand below the 

 chalk, and of those which formed the sandstone of the London clay. 



16. Pecten quinquecostata. Min. Conch, tab. 56. The lower or 

 convex valve only has been observed ; its form is precisely similar to the 

 chalk specimens. 



17. Perna. Impressions of the hinge of a species of this genus are 

 preserved in some of the masses of ironstone in my cabinet ; and a few 

 casts of the shell were discovered in the sand by my brother. The largest 

 specimen of the hinge is about three inches long, and exhibits six casts of 

 the pits or depressions of the original ; they resemble P. aviculoides, 

 Min. Conch, tab. QQ. in their general contour, bvit probably belong to a 

 distinct species. 



18. Terebratula ovata. Min. Conch, tab. 15. fig. 3. It is of an ovate 

 form, rather depressed, smooth, and obscurely pentangular. This species 

 also occurs in the green sand of Wilts. 



19- Terebratula; a small striated species, in too imperfect a state to 

 admit of determination. 



Proceeding towards the eastern division of the county, the sand is 

 observed holding its course in a Hue parallel with the northern escarp- 

 ment of the Downs, at Henfield, Hurstperpoint, Stonepound, Keymer, &c. 



In the pleasure grounds of W. J. Campion, Esq. of Danny, near 



