18 Dr. Wright on the Geology of the Isle of Wight. 



bands of bluish or slate-coloured clays with zones of Cyrena ob- 

 ovata of large size ; C cycladiformis, Potamides margaritaceus in 

 great profusion and perfection. It rises on the shore north of 

 cuff End, at a short distance from No. 1 ; its line of demarcation 

 from that bed is well defined by the thick fossiliferous band of 

 Cyrena obovata. I observed in this bed a few Cytherea incrassata. 

 It ascends at angles from 5° to 10°, and runs out on the cliff 

 north of Lynchen Chine ; it measures upwards of 21 feet, 

 and contains Melanopsis fusiformis, small Serpulce, and a small- 

 ribbed Modiola of the same species as that found at Hordle. 



No. 3. Lymn?ean limestone (No. 1) ; this rock contains bard 

 nodules which fall out on the shore, and much oxide of iron. It 

 is full of Lymnaa and Planorbis. 



A ledge formed of this bed stretches across the Solent towards 

 Hurst Castle. It rises on the shore at Cliff End, and blocks of 

 it are seen along the strand, from which good specimens with 

 their shells may be obtained. It measures about 3 feet, and is 

 interstratified with bands of blue clay. 



No. 4. Yellow sand rises at the south of Cliff End : its ori- 

 gin is concealed by the debris of the brackish series above. This 

 bed is well seen in the cliff between Lynchen and Bramble Chines, 

 and again at Warden Point. 



It contains few shells, and measures under Long's House 

 24 feet. It attains its greatest development at Headon Hill, 

 where it passes into a light-coloured calcareous rock, richly fos- 

 siliferous, with Lijmncea and Planorbis above, and small imivalves 

 and Melania below. 



No. 5. Laminated sandy clays, with sandy seams between the 

 layers of a slate coloui', and containing much iron which stains 

 the surface of the bed. They rise to the south of Lynchen Chine 

 and pass out beyond Warden Point, underlying the yellow sand, 

 and contain several fossiliferous seams. The following section is 

 taken at Warden Point : — 



Gray clay striped with fawn and red 4 feet. 



Gray sand 1 foot. 



Sand striped gray, blue and red 4 feet. 



Slate-coloured clay, with a band of Cyrena obovata . 6 inches. 



Potamomya plana is found in great abundance and perfection 

 in this bed. The fossiliferous seams are confined to the upper 

 and lower laminae. The lower strata contain many shells, and 

 form a well-marked band between this bed and No. 6. As it 

 passes through the cliff between Lynchen and Bramble Chines, 

 it inclines at an angle of 1°. Between Bramble and Warden Point 

 the angle increases to about 3". 



