which is composed of coarse sea-worn pebbles, partly of local 

 and partly of foreign origin; its height varies from 24 feet 

 to 53 foot, being lowest on the eastern side and highest on tho 

 western. Tho larger portion of its material is chalk-flint and 

 Greonsand Chert, some old gravel, angular flints, with a number 

 of Eed-Sand and Quartzite pebbles from the Budleigh Salterton 

 conglomerates of the New Hod Sandstone ; on its north-western 

 side tho raised beach is covered by a loam, containing land and 

 marsh shells, and is surmounted by a mass of debris, chiefly of local 

 rocks ; on its eastern side it caps the cliff, and contains an abun- 

 dance of marine shells similar to those now inhabiting the shore 

 and rocks such as Littorince, Purpura, Trochi, Mytili, &c. Tho 

 sands with which they are intermixed contain shells similar to 

 those which frequent the present coast-line, such as Riesoa, 

 Skenece, also the bivalve Cyanium minimum, now rare in the locality, 

 but abundant in the north of Europe. Some of the pebbles of 

 this bed are cemented together into a conglomerate by a mix- 

 ture of carbonate of lime, there are also tufaceous deposits 

 here and there, originating from springs, which at the time of 

 deposition must have been more highly charged with lime than 

 are the present neighbouring springs. Although the Middle 

 Purbecks do not now exist in situ on the Island, there is an 

 angular debris of this formation, which may be accounted for by 

 their removal during the several changes of level to which the 

 Island has been evidently subject, and which left the lower 

 unfossiliferous beds of the series exposed. These changes have 

 materially altered the coast-line, and aided by the powerful 

 Atlantic wave extensive encroachments have been made ; the few 

 existing raised beaches between Devonshire and Sussex point to 

 this conclusion. A Mammaliferous drift-bed of red clay passing 

 into a coarse loess south of the Ven is now almost entirely 

 removed ; it is here the Portland stone and over-lying Pur- 

 becks are extensively quarried. The Dirt-bed, from 12 to 18 

 inches thick, forms the basement of tho latter formation, contain- 

 ing a large per centage of earthy lignite, and is evidently an 

 ancient vegetable soil. Silicified trunks of coniferous trees and 

 the remains .of plants allied to Zamia and Cycas are buried in 

 this Dirt-bed ; stumps of these trees stand erect, and thoir stems 

 lie prostrate, partly sunk into the black earth and partly envel- 

 oped by a calcareous shale, which covers tho Dirt-bed. During 

 the walk the botanists collected several plants, including Trifolium 

 maritimum, Trifolium scabrum, Vicia gracilis, Armcria, maritima, 

 Borago ojficinalis (very abundant both among the rocks and in the 

 fields), Phleum arenarium, Euphorbia Parah'as, also, the follow- 

 ing throe, which are of especial interest, Valerianella eriocarpa, 

 Spergularia rupestris, Muscari racesmosum. On thoir return to 

 Weymouth the party repaired to tho Burdon Hotel, where dinner 

 was provided, and to which about twenty members sat down. 



