132 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Juiie 23, 



these I have got myself. I also saw in the possession of one of the 

 *' navvies" a fragment of a shell resembling a Nerincea, in remark- 

 ably fine preservation. 



The altitude of the railway-cutting above the level of the sea, as 

 I learn from the engineer on the hne, is 250 feet. At the time of 

 my visit the excavation had reached a depth of from 10 to 15 feet, 

 and the " navvies " were busy at work in the " gullet," filling their 

 waggons with the clay, which is a mass of a fine greenish-blue colour, 

 very compact and tenacious, and unlike any other clay in this part 

 of the country. It consists of a fine impalpable mud, devoid of all 

 manner of stones or pebbles, save occasionally a hard greenish nodule, 

 enclosing the remains of a large Ammonite. 



This clay is covered by a stratum of the Pleistocene Drift, of a 

 brownish-grey colour, very sandy in some places, and of a more 

 clayey nature in others. In this drift I found many striated 

 fragments of clay-slate, together with bits of other primary rocks. 

 The line of junction between the two beds is very undulating and 

 irregular ; in some places the Lias-clay reaches nearly the surface 

 of the ground with a well-defined outline ; while in others it is 

 covered by several feet of the drift, which, towards the southern 

 end of the cutting, appears to occupy almost the whole of the ex- 

 cavation, the Lias being wasted almost wholly away, and imparting 

 in some places to the overlying mass a dark-bluish hue, and a more 

 clayey nature, so that the Ime of junction becomes less defined. The 

 bottom of the Lias- clay had not been reached, so that I did not see 

 what it rests upon ; but the old clay-slate comes to the surface within 

 a stone's throw of the spot, and is found in the neighbourhood aU 

 around; so that we have here but a small remnant — the merest 

 patch — ^left of this interesting deposit. 



The most abundant fossil is the Ammonite, of aU sizes, from indi- 

 viduals of a quarter of an inch in diameter to five inches. The nacreous 

 lustre of these shells — especially in the smaller and more dehcate 

 specimens — is generally in beautiful preservation. These Ammonites 

 were most plentiful at the north end of the section, where the cutting 

 was commenced. In some places every spadeful contained dozens of 

 delicate thin-sheUed Ammonites, much decayed, but still preserving 

 their rainbow-Hke lustre. Owing to the progress of the work, and 

 the sloping of the sides, they are now more dijficult to be obtained. 

 Next to these, the most common organism is a large bivalve like a 

 lAmay measuring 4 inches in the longest direction, by 3^ inches 

 across. Part of the brown- coloured shell remains in complete pre- 

 servation ; and both valves are in conjunction and shut, the interior 

 being filled with a greenish-coloured mass of the same appearance 

 as the surrounding clay, but of a more stony texture. 



The clay in some places contained the decayed remains and im- 

 pressions of many smaller shells, from 1 inch to 1^ inch in size, and 

 having the characters of Lima. 



Broken pieces of Belemnites are also not very unfrequent ; also 

 specimens of a Gryphceay measuring 5 inches in diameter, resembling 

 0. incurva. Among some specimens, which I owe to the kindness 



