140 GEOLOGY OF THE ISLE OF WIGHT. 



depth of 200 feet. At Parkhurst barracks, a wel! 

 was dug through 300 feet of London clay, con- 

 taining a few thin seams of shells. On examining 

 the nature of the soil in the tract between the 

 town and the neighbouring chalk hills, the ver- 

 tical marine strata are found occupying the same 

 relative position as at Whitecliff Bay.* In a heap 

 of clay that had recently been dug up from the 

 bottom of a well, Mr. Webster discovered vestiges 

 of coleopterous insects ; and obtained several fossil 

 seed-vessels of a plant related to the Meadow-rue 

 (Thalictrum) ; they consisted of the pericarp, in a 

 carbonized state, filled with clay.-j- 



The quarries in the neighbouring chalk down of 

 Mountjoy, to the southward of the town, expose 

 some interesting sections of the highly inclined 

 strata of chalk and flint ; and the summit of the 

 hill commands a most extensive and delightful 

 prospect. 



River Medina. — The Medina river, which 

 rises at the foot of St. Catherine's Down, and 

 divides the Island into two nearly equal portions, 

 called the East and West Medina, flows through 



* Mr. Webster notices a clay-pit, opened for a brick manufactory, in which 

 were clay and sand strata, in a nearly vertical position, and the upper por- 

 tions contorted .is if from pressure. Sir H. Englefield's " Isle of Wight," 

 pi. xxxiv. fig. 1. 



t A figure of this fruit (which has been named by M. Adolphe Brongniart, 

 Thalictroide* Weblteri,) is given in the " Medals of Creation," vol. i. p. 190. 



