112 Mr. H, T. De la Beche on the Chalk and Sands beneath it. 



Chambered Univalves. 



Nautilus (2 species.) 



Ammonites varians Sow. (Min. Con. Tab. 176.) 



rhotomagensis . Defr. (Env. de Paris, PL VI. fig. 2.) 



Coupei A. Br. (Env. de Paris, PI. VI. fig. 3.) 



constrictus . . . Sow. (Min. Con. T. A.) 



Scaphites 



Turrilites Bergeri A. Br. (Env. de Paris, PI. VII. fig. 3.) 



Belemnites. 



Univalves. 



Trochus Gurgitis A. Br. (Env. de Paris, PI. IX. fig. 7.) 



? Rhodani A. Br. (Env. de Paris, PI. IX. fig. 8.) 



Bivalves. 



Cucullaea carinata Sow. (Min. Con. T. 207. fig. 1.) 



Trigonia aliformis Sow. (Min. Con. T. 215.) 



Pachymya * Sow. 



Plicatula. 



Gryphaea columba Sow. (Min. Con. T. 383.) 



Ostrea vesicularis Lam. (Env. de Paris, PI. III. fig. 5.) 



Terebratula subrotunda . . Sow. (Min. Con. T. 15. fig. 1, 2.) 

 plicatilis .... Sow. (Min. Con. T. 118. fig. 1.) 



Sands and Sandstones beneath the Chalk near Lyme Regis. 



These may, for the convenience of more easy description, be divided into 

 three parts, viz. yellowish-brown Sandstone with chert-seams; yellowish-brown 

 Sand (commonly called "^Fox Mould" by the people of the country); and Sands 

 and Sandstones containing an abundance of green-earth, from which circum- 

 stance the term Green-sand has been very generally applied to the whole of 

 the above sands and sandstones in this district; — these taken together con- 

 stitute a thickness of nearly 200 feet. 



Yellowish-brown Sandstone loith chert-seams. — This division commences 

 immediately beneath the very compact bed, mentioned under the head of Chalk 

 with quartz-grains. The upper portion of this Sandstone, for the thickness of 

 12 feet, does not contain the chert in regular seams, but merely in detached 

 pieces ; here and there we observe portions of green-earth, with thin veins and 

 specks of oxide of iron. This upper portion contains the teeth, vertebrae and 



* This new genus has been figured in T. 504 and 505 of Sowerby's Mineral Conchology. 



