118 LIAS OF ENGLAND AND WALES: 
It is curious that the stones gathered from the higher part of 
the beach where they are sun-dried, are said to be not so good for 
hydraulic lime ; but they are burnt for local purposes at the Lime- 
kiln near Ocean House, West Aberthaw, where " lump lime " 
and " ground lime " are prepared. 
East of the Kiver Daw, by Pleasant harbour, the platforms of 
rock contain Gryphtea arcuata, and Lima gigantea. The cliffs 
for some distance show hard blue limestones in tolerably thick 
beds, dipping gently eastwards, and yielding the same fossils 
together with Ammonites. 
At Bridgend the limestones of the Lower Lias have been 
extensively quarried for building-stone and for Blue Lias lime, 
which lias been put on the market under the name of " Aberthaw 
lime." The railway -cutting also shows fine sections of the beds, 
and these were described in detail by Charles Moore, who recorded 
an alternation of 476 beds of limestone and marl. The lower 
portion of the series is worked in the quarry, but we do not see 
the base of the Lias ; blue earthy limestones were the lowest beds 
to be seen, and they are overlaid by compact and earthy bluish- 
grey and yellowish limestones. Altogether upwards of 76 beds 
of limestone were exposed in the quarry, for the most part in 
thick beds with comparatively little clay. The fossils which I 
obtained, included Gryphcea arcuata (and broad varieties), Ostrea 
irregularis, Lima gigantea (large specimens), Pholadomya ambigua, 
Homomya, Unicardium cardioides, and Pleurutomaria. By the 
entrance to the quarry from the railway, the Lias contains len- 
ticular nodules of chert or siliceous limestone, in which Dr, Hinde 
(to whom I sent specimens) found rod-like sponge- spicules. 
Ammonites Bucklandi occurred here, and I obtained also a large 
specimen of Cerithium nodulosum at the base of the railway- 
cutting.* 
Moore published a list of the fossils obtained by him, including 
Ammonites angulatus, A. Conybearei, and (in the higher beds) 
A. semicostatus and A. sauzeanus.-\ He also noted a number of 
Gasteropoda. The beds correspond with those seen in the cliffs 
between Dunraven and Aberthaw, and, like them, include portions 
of the zone of A. angulatus, the zone of A. Bucklandi, and that 
of A. semicostatus. 
Turning to the borders of the Bristol Channel and the Severn, 
we find several tracts of Lias. These show that the main 
portion of the estuary must have been originally excavated through 
the Lower Lias, the now isolated tracts of which may, in com- 
paratively recent geological times, have been connected with the 
main mass of Lias at Gloucester, and with the portions preserved 
at Aberthaw on the north and at Watchet on the south of the 
Bristol Channel. In these areas we have seldom preserved any 
beds newer than the zone of Ammonites semicostatus, excepting 
in such a locality as Brent Knoll. 
* The fossils \vere named by Messrs. Sharman and Newtou. 
t Quart. Jeurn. Geol. Soc., vol. xxii., pp. 513-517. 
