MOOKE AUXORXAL SECONDARY DErOSITS. 487 



Solarium lunatum, Moore. , Turbo soliclus, Moore. 



, sp. 



Amber ley a Alpina, StoL, sp. 



Fish-teeth and scales. 



Belemnites, fragments. 



Corals derived from the Carb. Limest. 



Trochus Holwellensis, Moore. 



latilabrus, StoL 



gradatus, Moore. 



Plem-otomaria Buchi, Desl. 



Turbo Orion, Z>' Orh. 



nodulo-carinatus, Moore. 



3. The MicrolestesQuarrij. — Passing again into the Shepton-Mallet 

 road, from the section just noticed, several fine sections of Carbo- 

 niferous Limestone may be studied. The first reached on the left 

 is that from which I obtained so wonderful a harvest of Ehoetic 

 remains, — to which I propose to devote a special paper. The vein 

 whence they came could then be traced taking an irregular east 

 and west direction, and was probably a continuation of one of those 

 described in the large section below. The limestone has since been 

 worked back, and its position almost obliterated. Several other 

 small veins may be noticed in this quarry, generally filled with a 

 dense yellow or pinkish conglomerate, with occasional traces of 

 Ehaetic remains. Purther up the road, on the same side, are other 

 openings in which similar phenomena occur ; but these we need not 

 particularize. 



Just above the ^[icrolestes Quarry, on the opposite side, is, how- 

 ever, a remarkably fine section belonging to the Earl of Cork and 

 Orrerv, which deserves notice, and is the last I shall allude to at 

 Holwell. 



On entering this quarry a very long section is seen, the floor of 

 which is formed of Carboniferous Limestone dipping rapidly to the 

 south. The north side of the middle part of the quarry is formed of 

 a high wall of Carboniferous Limestone. At the eastern end of this 

 may be observed the face of a dyke of Lias, four feet mde, which in 

 its passage westwards has been left standing as unprofitable material 

 by the quarrymen, being chiefly composed of carbonate of lime. A 

 section of the vein itself at this point shows that, within the lime- 

 stone walls of the vein, there have been deposited vertical layers of 

 crystalline carbonate of lime, and then, occupying the centre of the 

 vein, an inner deposit of Lias, from which were obtained Griiplicea 

 incurva, RliynchoneUa furcilJata, Belemnites, Avicula , &c., Liassic or- 

 ganisms showing themselves abundantly on its weathered sides. At 

 the western end this vein thickens to ten feet, and is there cut oft' 

 by a north and south vein ^4th indications of iron-ore, beyond which 

 it can be traced in other workings to a considerable distance. At 

 the southern entrance to the quarry another very thick dyke of Lias 

 is present, against which a mass of thick-bedded Carboniferous 

 Limestone has been left standing. "When the material of these 

 dykes is composed of limestone, which often happens, it so accommo- 

 dates itself to the angular irregularities of the older rock as to ap- 

 pear, when worked back upon, to be only a continuation of the 

 same, the bedding seemingly passing from one into the other, and a 

 careful examination is needed to distinguish the diftcrence. AMien 

 standing on the floor of this large section it is difiicult to realize that, 

 with the Carboniferous Limestone beneath your feet and everywhere 



