in the Vicinity of Lyme Regis, Dorset. 23 



those of Golden Cap. The following list details the beds^ in a descending 

 order, in the section disclosed at the base of Black Ven. 



Section of the Upper Marl beds of the Lias, at the Base of Black Ven. 



Thickness. 

 Ft, In. 



Marls and slaty marls, with several 



beds of indurated marl and ^ 100 



earthy limestone. 

 Irregular bed of limestone, with 



rounded nodules, frequently ^ 2 



containing ammonites . 

 Slaty marls, with several thin beds 



of indurated marl . 





67 



Thickness. 

 Ft. In. 



Slaty marls, containing small cry- 1 



stals of selenite . . . } 



Indurated marl, containing small 1 



plicated terebratuliE . . J 



Slaty marls 18 



Earthy limestone . . • .04 



Marls and slaty marls (above alime- 1 

 stone bed ten inches in thickness) J 



32 

 4 



5 



Organic remains are abundant in some parts of the lias marl: — flattened 

 ammonites occur in some of the slaty varieties ; but the best preserved speci- 

 mens of that genus are found in the rounded nodules of argillaceous limestone 

 which occur within the marls. — These are of various species ; such as A. ob- 

 tusus, A. armatus, A. stellaris, &c. Plicated terebratulae are also common. 

 And the marls also contain the remains of Ichthyosauri, Plesiosauri, Penta- 

 crinites, lignite, &c. The Gryphasa incurvaand Plagiostoma gigantea, though 

 found in the marly beds, are more abundant in the limestones of the lias. 



II. The Lias Limestones may be said to commence with a series of thin 

 beds varying from earthy to compact, and alternating with thin beds of marl. 

 They rise from beneath the marls on the western side of Black Ven, and con- 

 tinue from thence to the Church-Cliffs immediately on the east of Lyme ; 

 but four or five small faults throw them down, and prevent their rising so high 

 at Lyme as they otherwise would have done : and at that place there must be 

 a considerable fault, — probably in the line of the long ledge, dry at low water, 

 which extends into the sea opposite the eastern part of the town ; since the 

 lias marls are there again brought down nearly to the level of the sea, and 

 are continued from the town to the western side of the Cobb. — It is clearly 

 seen that this marl is not inferior to the limestones of the Church-Cliffs 

 (between the Cobb and the town of Lyme) ; for both the marls and the 

 limestones can be identified on each side of the town. 



From a short distance west of the Cobb, to Seven-rock Point*, the lias 

 limestones are exposed at the lower part of the cliff; and the cliffs afford a 



* This name is erroneously printed " 5'aren-Rock.Point " in Plate VIII. vol. i. 



