‘ 
449 
In Aberreiddy Bay, about twelve and a half miles to the south- 
west of Dinas, slaty beds with a northwardly dip, and apparently 
prolongations of the schists on the line of section, contain the Grap- 
tolithus Murchisonii and G. foliaceus of the Llandeilo flags, also nu- 
merous casts of an Euomphalus, resembling the K. perturbatus of 
that formation, and a species of Lingula. Although these slates 
differ in lithological characters from the Llandeilo “flags, yet Mr. 
Maclauchlan is of opinion that this difference may have been pro- 
duced by the masses of trap which are associated with the slates. 
The conglomerate sandstone of Dinas Head, which occurs also in 
Newport Bay and at Trewyddel, near Cardigan, is stated to resem- 
ble one of the conglomerates of the Caradoc sandstone described by 
Mr. Murchison ; and the crinoidal stems which it contains, to agree 
with analogous remains found by Mr. Murchison in the Caradoc 
sandstone at Little London, May Hill *. 
In addition to the phenomena which occur in the immediate vi- 
cinity of the section, Mr. Maclauchlan alludes to indications of anti- 
clinal lines near Narberth and at Camrose, in Southern Pembroke- 
shire ; also at Solfach, south-east of St. David’s, and at Porthllisky, 
to the south-west of that city. At the latter village the dip changes 
to the westward, and continuing to alter, assumes in Whitesand Bay 
a northwardly direction. This dip also prevails at St. Laurence, 
thirteen miles east of St. David’s Head; at Leweston, three miles 
south of St. Laurence, and at Long Ford, about two and a half miles 
south of Llandysilio. Trappean ash also is stated to oecur near green- 
stone at Penbury (Penberry, Ord. Map) Hill, two and a half miles 
north-north-east of St. David’s; at Lianllawer, two miles south-east 
of Fishguard; and at Carningley, one mile south of Newport. 
Though the summit of the principal Pembrokeshire chain is 
roofing-slate, yet. trap-rocks occur near the top, and are described by 
the author as continuous through the district, extending to Plumb- 
stone Mountain (five miles north-west of Haverfordwest) and to St. 
~David’s Head, reappearing at the Bishop and Clerks and the Hat 
and Barrels rocks, and at the Smalls light-house. At Fishguard and 
Strumble Head, three miles west of Fishguard Bay, the trap is co- 
lumnar. On the north-east of the chain at Whitechurch (Eglwys- 
wen), six miles south-east from Newport, on the east at» Llanfirnach 
(Llanfrynach, Ord. Map), and on the south at Llanglwydwen, are 
beds of dark carbonaceous shale, which have been fruitlessly worked 
for culm; they appear to mantle round the trap, but preserve a 
northerly dip; they are accompanied by lead-veins, one of which, at 
Lianfernach, has been worked-successtully. At Llanglwydwen Bridge 
are indications of copper in a lode in contact with a considerable 
bed of limestone. Mineral veins also exist along the coast, from 
Newgate, in St. Bride’s Bay, to St. David’s Head. 
6. “ Description of some remains of a gigantic Crocodilian Sau- 
rian, probably marine, from the Lower Greensand at Hythe; and of 
* Silur. Syst., Plate 20, fig. 19. 
