98 Dr. Wrio-ht on the Geology of the 



No. 30. Dark olive-green clay, with a band of Lymnaa and 

 Pkmorbia in its upper part, and masses of nodular ironstone be- 

 low. Several of these have rolled out of the bed and lie on the 

 shore at Tollands Bay : measures 4 feet 6 inches. 



\o. 31 . Grayish white sand, rises on the north side of Weston 

 Chine ; is exposed at the base of that ravine, is covered up with 

 grass in the remainder of its course through Tollands Bay, and 

 concealed by debris on the north side of Headon. It is seen 

 however in situ on the southern escarpment of that hill. The 

 anticlinal axis figured by Webster in his coast section of Tol- 

 lands Bay is very well seen from the water. No. 23 of our sec- 

 tion is the bed which appears to droop most. The angle of de- 

 clension is not more than 2° : upwards of 20 feet ? 



The remaining beds of the lower freshwater series are not seen 

 where they rise from the shore in consequence of the debris, 

 which has fallen and covered them up at their origin and through 

 the greater part of their course. Beyond Alum Point several of 

 the lower beds are seen in situ, but they are best exposed in the 

 sand-pit at present worked. The following section gives an ac- 

 curate measurement of the 26 feet of sands and marls that repose 

 upon the pure white sand. The angle of inclination is about 1°. 



ft. in. 



32. Light gray sand with few freshwater shells 2 4 



33. Compact gray marl full of compressed Lymnaei, &c. .. . .9 

 ., , J Greenish stiff clay 5 9 



' 1 Seam of lignite, vegetable structure shown 3 



o- f Greenish clay, very tough and tenacious 6 



' \ Seam of lignite, about 3 



o£ J" Gray sand 2 4 



J0, \ Seam of lignite 5 



37. Yellow clay, ochre-coloured 4 9 



38. Yellow sand 4 4 



This forms the floor of the section. 



39. Fine white sand. The uppermost bed is a very fine pure 

 white sand dug for making glass, and is largely exported for that 

 purpose. It has proved a California to the proprietor, as it is 

 sold for about 14s. a ton. The white bed passes into one of a 

 pale ochre colour, and then into another of a deeper tint striped 

 with yellow bands. The thickness of the sands at Headon Hill 

 is unknown, as the bed dips beneath the sea. The equivalent bed 

 at White Cliff Bay measures 200 feet in thickness. No fossils 

 have been found in this bed. I observed only fragments of 

 shells, too minute and water-worn to ascertain to what genus 

 they belonged. 



Barton Clay Group. 



No. 40. A great bed of brownish clay which consists of several 

 subordinate beds. It forms " stratum B " of Webster's sec- 



