PALAEONTOLOGY OF THE LIAS. 63 



studying these beds, from the fact, that at the base of the 

 Maristone resting on the higher members of the lower Lias, 

 there are beds of yellow micaceous sand, very similar to 

 the lowest beds of the Inferior Oolite, and which may be 

 readily mistaken the one for the other, and the more so 

 from their containmg but few distinctive organic remains. 

 On the lower sand are the workable beds of the Maristone 

 or middle Lias, which have a thickness of from ten to twenty 

 feet. Next in ascending order is a thin bed of greenish 

 sand, principally characterized by containing innumerable 

 Belemnites, an internal shell to an animal like the Cuttle 

 Fish. These Belemnites also abound in the stone below. 

 Then comes another thin bed of stone. With this the 

 middle Lias terminates, and with one solitary exception, 

 there is an entire change in the nature of the organic remains 

 from those contained In the beds above. The upper Lias 

 commences with laminated clays about two feet in depth. 

 About the centre of these there is an occasional bed of 

 yeUow limestone, having an average thickness of three or 

 four inches, than which, from the nature of the remains it 

 encloses, or for the beauty of theh' preservation, there can 

 rarely be a bed of greater interest. Above succeed thin 

 bands of rubbly stone and clay, on which, above all, is seen 

 the sand of the Inferior Oolite. One of the best sections 

 may be seen at Shepton Beauchamp, near Ilminster. 



Compared in thickness with the great series of formations, 

 the beds I am speaking of appear insignificant, and their 

 development is not considerable. At Ilminster they have 

 a ränge of a few miles towards South Petherton and Yeovil; 

 they are found on the Tor Hül at Glastonbury, at Eadstock, 

 in the cutting of the Railway at Box, again at Cheltenham, 

 after which I am not aware that they are found until the 

 Yorlcshire coast is rcached. 



