484. TRANSACTIONS OF SECTION C. 
the appointment of Government ecological surveys by those already officially 
in charge of geological work, in view of the assistance each science can render 
the other. Whilst emphasis is here laid on the value of ecology to the geologist, 
equal value is rendered by the geologist to ecology. The author illustrates these 
principles by examples from an ecological survey of Leicestershire, where he 
has found that a knowledge of rock soils and plant distribution has supplemented 
the evidence of geological data. It is thought that geologists generally may 
not be fully aware of what is being done in a different field, and the significance 
of rock-soil work to them may have been overlooked. 
10. Report on the Erratic Blocks of the British Isles. 
See Reports, p. 145. 
11. Report on the Investigation of the Igneous and Associated Rocks 
of the Glensaul and Lough Nafooey Areas, Co. Galway.—See 
Reports, p. 150. 
12. Interim Report on the Prepeeaiee of a List of Characteristic 
Fossils. —See Reports, p. 150. 
13. Preliminary Report on the further Exploration of the Upper Old 
Red Sandstone of Dura Den.—See Reports, p. 150. 
SSS = 
MONDAY, SEPTEMBER 15. 
The following Papers and Reports were read :— > 
1. The Geology of the District between Abereiddy and Pencaer, Pem- 
brokeshire. By A. Husert Cox, M.Sc., Ph.D., F.G.S., and 
Professor O. T. Jones, M.A., D.Sc., F.G.S. 
In an introductory paragraph the authors referred to the work of previous 
observers, namely, Hicks, Reed, Elles, and Elsden, and to the visit of the 
Geologists’ Association during Easter, 1910, when results were obtained which 
suggested that this area required re-investigation. Examination by the authors 
has proved that the apparent sequence is extremely complicated by strike- 
faulting, and instead of Llandeilo and Bala rocks, as previously supposed, 
Arenig and even Cambrian rocks form large areas of the coast. 
Part I. Abereiddy Bay to Pwll Strodyr (ASH C.): 
The ground is occupied by the under-mentioned beds, the stratigraphical 
order of which is, so far as known, as follows :— 
Bala . .  .  . Limestone of Eastern Quarry, Abereiddy=Mydrim Limestone 
of Carmarthenshire. 
Llandeilo . .  . Lower Dicranograptus Shales=Hendre Shales of Carmar- 
thenshire. 
{ Didymograptus Murchisoni Shales. 
Tia ee Didymograptus Murchisoni Voleanics (including the 
. . | Abereiddy Ash, and Llanrian lavas). 
Didymograptus bifidus Shales. 
[ Tetragraptus Beds—dark slates. 
Porth Gain Beds—egrits and slates with Orthis calligramma, 
| var. proava. 
Abbevouarle Beds—sandy mudstones with Ogygia selwyni, &c. 
? gap. 
Areni¢ . 
