114 LIAS OF ENGLAND AND WALES : 
specimens showing this structure ; he evidently referred to iron- 
hot beds, such as occur in Somersetshire near the Mendip Hills. 
(See p. 127.) 
Near Langan, the conglomeratic beds of Lias spread over a 
large area and are based upon the sands and shales of the Rhaetic 
Series, as pointed out by Bristow.* According to Moore a sinking 
at Langan Lead-mine proved the following beds : } 
FT. IN. 
Dense limestones with thin intervening beds of marl,"! 
regularly bedded but finely conglomeratic - ' L 1 5ft ft 
Sutton Stone f 
Unstratified conglomerates [P base of Sutton Series] - J 
This great thickness of strata may be compared with that in the 
ravine of Pant-y-Slade, previously mentioned (p. 100). 
At St. Mary Hill Common, on the south side, west of 
Tyrmynnyd, the Sutton Stone has been worked. According to 
Bristow the beds are slightly conglomeratic, containing frag- 
ments of black chert, small pebbles of white quartz, and specks of 
galena. The following species were obtained : 
Cardinia suttonensis. 
Lima. 
Modiola. 
Ostrea liassica. 
Pinna. 
Pecten suttonensis. 
The following section was exhibited at the Cement-works on 
Stormy Down : 
FT. IN. 
Brown clay. 
Hard compact blue limestones and shales, with 
Unicardium, ike. ... - 3 6 
Lower Lias. 
Zone of 
Ammonites 
planorlis. 
Even beds of shaly limestone and shales - 2 
Dark blue shaly limestones, with near base, beds of 
blue limestone and shale containing Ostrea liassica 
and Modiola minima - - about 18 
Conglomeratic Bed : pale grey and bluish brecciated 
and shelly limestone ... about 10 
"Limestone-shales - 8 
Hard compact limestone (like Sun bed) - 10 
Shaly parting. 
Rhsetic J Hard compact and rather shaly limestone - 8 
Bi'ds. ] Black shales with thin bands of limestone, Pecten 
valoniensis - - - - 1 
Grey and greenish marls with hard nodules (formerly 
[_ used for cement) seen to depth of - 36 
Bristow, who regarded the conglomerate as the attenuated 
representative of the Sutton Series, noted its thickness as 2 feet, 
and described the bed as a "hard, siliceous, and shelly blue 
conglomerate.''! Mr. Tomes describes the bed as from 2 to 3 
feet thick, and as in all respects like the " Guinea-bed " of Binton 
in Warwickshire, a bed which he regards as the equivalent of the 
White Lias. It may be remarked, however, that a conglomeratic 
* Quart. Journ. Geol. Soc., vol. xxiii. p. 204. 
| Ibid., p. 533 ; Tawney, Ibid., vol. xxii. p. 74. See also Tomes, Ibid., vol. xl. 
p. 361. 
t Ibid., vol. xxiii. p. 204. 
Ibid., vol. xl. pp. 358, 359 ; see also Lucy, Proc. Cotteswold Club, vol. viii. p. 256. 
