Yol. 67.] WEST, MID, AND EAST SOMERSET. 43 



The bottom-beds of the Lower Lias that were seen, corresponded 

 precisely with the similarly-numbered deposits exposed in the 

 cutting on the west-north-west — that through which the line 

 passes immediately before crossing the Cary River. 



The Langport Beds were exposed in their entirety, measuring 

 20 feet 8 inches. A bed crowded with the branching coral Theco- 

 smilia, and comparable with that noticed by Moore at Long Sutton 

 many years ago, 1 constituted a notable horizon. Here the Langport 

 Eeds fall naturally into five groups — the massive ' Sizes' at the base, 

 and the more rubbly beds near the top. Even in this fine develop- 

 ment there is oft-recurring evidence of slow formation afforded by 

 the waterworn and channelled surfaces of the massive ' Sizes,' and 

 by the manner in which the specimens of Dimyodon intus-striatus 

 adhere to the upper surface of the limestones and encrust the 

 pebbles in the intervening marly layers. 



The Cotham Marble was not detected, but its stratigraphical 

 position was obvious, and it was discovered at that horizon in the 

 cutting near the Cary River (see p. 45). 



Between the Cotham and the Lilstock Beds occur locally 

 huge masses of hard limestone coated with shell-debris. Similar 

 masses occur at Sparkford Hill on this horizon, and emphasize 

 the temporary discontinuance of sequential deposition — of which 

 evidence was also afforded at St. Audrie's Slip near Watchet. 



Bed 9 was a readily-recognized and conspicuous stratum, for its 

 large septariform nodules were scattered over the floor of the 

 cutting at the foot of the bank, down which they had rolled. 



The Bone-Bed (15) at Charlton Mackrell is a hard grey siliceous 

 sandstone, intermediate as regards texture between the Bone-Bed 

 of the Blue-Anchor foreshore and that at Lilstock. Streaks of 

 impure, grey, micaceous limestone traverse the bed ; but in such 

 vertebrate-remains are few, being most abundant in the sandstone- 

 portion. 



The basal Bone-Bed (20, lower part) is a grey indurated sandy 

 mudstone, with flakes of marl which impart to it a laminated 

 appearance. 



Cary-Bridge cutting. — Continuing along the railway in the 

 direction of Somerton, a cutting through a highly-faulted outlier 

 of Rhgetic and Liassic rocks is traversed before reaching the 

 viaduct over the Cary. 



Entering the north-eastern end of this cutting, we perceive 

 first of all traces of the red marls, with the Pteria-contorta Shales 

 faulted against them. Then succeed prominent limestones about 

 the horizon of stratum 3 of the Cotham Beds, followed by bluish 

 shales as at Charlton Mackrell. Above is the whole of the Lang- 

 port Beds with the prominent Thecosmilia Bed about their middle, 



1 Q. J. a. S. vol. xvii (1861) pp. 491-92. 



