in the Counties of Monmouth, Glamorgan , &c. 347 
of considerable magnitude, lies between Ystradvellte and 
Penderryn, where all the strata on the north side of the bason 
are moved many hundreds of yards southward (as at Dinas). 
18. Note. The limestone appears to the surface all along 
the boundary line in the counties of Monmouth, Glamorgan, 
Carmarthen, Brecon, and no doubt can be entertained of its 
due range from Newton across Swansea Bay to the Mumbles, 
and from Llanmaddock Hill across Carmarthen Bay to Tenby. 
In Pembrokeshire it appears to the surface on the south side 
of the bason, at Tenby, Ivy Tower, Cochelard, Bit Church, 
Williamston, Lawrinny, Cord, Canta, and Johnston ; and on 
the north side of the bason, at Templeton, Picton, Harriston, 
and Persfield ; yet it certainly forms an underground con- 
nection from point to point. 
