118 



GEOLOGY. 



For the next twelve beds some of which are much disturbed, 

 he has substituted the following section. 



Character of Rock. Tliickness. Organic Remains. Quarry List, 



M Broken 

 I bands 



ft. in, 

 Blue shales, with 

 occasional hard | 

 bands 22 



c 

 128 



129 



i Ditto, harder 

 Blue cypris shales 

 Olive brown marl- 

 stone 

 Hard yellowish cal- 

 careous shales, 

 about 



4 



16 



Cypris, Archseo- 



niscus 

 Archaeoniscus 



The continuation of the section down to the Portland Oolite, 

 can be best obtained at the edge of the cliff beneath the western 

 extremity of Round down, over what the fishermen denominate 

 "Gunner's hole." At page 15, I suggested the probability that 

 the Portland dirt-bed and fossil forest extended eastward beyond 

 Kimmeridge. I have since ascertained that such is undoubtedly 

 the case. About the period of my making the above statement, 

 I observed, in a stone pit situated to the south of Kingston, 

 several blocks of alithological character with which I was at that 

 time imacquainted, but upon visiting the dirt-bed at Lul worth, 

 I recognized its identity with the porous limestone of that deposit, 

 which Mr. Fisher describes in the following terms: " The 

 stumps of the trees sometimes remain in a silicified state, but 

 more frequently they have disappeared. The spot where each 

 stood is surrounded by a dome-shaped swelling of the bed of 

 porous limestone which covers the dirt-bed. These domes have 

 generally a pit in the centre where the trunk protruded, but 

 some have not. Such perhaps may have covered Zamias. 

 Other swellings of the bed are long and trough-shaped, having 

 accumulated about fallen trees. The surface of this bed of stone 

 is very irregular, and it has much the character of the deposit 

 from a petrifying spring on moss. No carbonaceous matter is 

 present, except in the ancient soil beneath." At Round-down, 

 the surface presents a like character: it was its peculiar and 

 rugged appearance which first attracted my attention, but no 

 stumps of trees occur in sitUj although I found amongst the 



