TRANSACTIONS OF THE SECTIONS. 83 
Upper Bann or the Blackwater does now. (5) That these clays are of considerably 
later date than the basalt, and that the silicified woods may with all probability be 
referred to the latter. (6) By the help of these clays we learn that the existing 
physical geology, and the main features of the surrounding country, are due to a 
period newer than the age of the basalt, but more ancient than the great Glacial 
epoch, and that the great denudation which has affected the north of Ireland at 
least belongs to the same time. 
Sketch of the Geology of the N.E.of Ireland. By Professor Harness, ERS. 
On the Progress of the Geological Survey of Ireland. By Prof. Hutt, F.R.S. 
In exhibiting the new Index of Geological signs and colours, which had just been 
prepared for the Geological Survey of Ireland, Professor Hull gave a short sketch 
of the origin and progress of the Survey, observing that it had originated in 1832 
with that of the late General Portlock and his assistants, who had published the 
well-known ‘ Report on the Geology of Londonderry, Tyrone, and adjoining districts’ 
(1848). Along with this it had been intended to publish exhaustive reports on 
the botany, zoology, and mineralogy of the districts; and Mr, Oldham, afterwards 
the Director of the Survey, was appointed to undertake the last-named department. 
Afterwards, however, the project of extending the Survey to other branches of 
Natural History than that of Geology was abandoned ; and it was determined by the 
Government of Sir Robert Peel to consolidate the Surveys of the United Kingdom 
under one head, and Sir H. T. De la Beche was appointed the first Director-Ge- 
neral (in 1844), while the Geological Survey of Great Britain was placed under the 
immediate direction of Professor Ramsay, and that of Ireland under Captain (after- 
wards Colonel) Sir H. James, who was succeeded by Professor Oldham, with a small 
staff of assistants. These officers commenced operations in the vicinity of Dublin, 
and southward through Wicklow into Wexford. On Professor Oldham being 
appointed to the Geological Survey of India, he was succeeded in the Directorate by 
the late Professor Jukes, who, with a slightly increased staft of surveyors, including 
the late Mr. Du Noyer and Mr. Kinahan, the present District Surveyor, completed 
the survey of a very large portion of the south, centre, and west of Ireland. 
The districts recently completed are those of Connemara and West Mayo by Messrs. 
Kinahan, Warren, and Symes, of the Mourne Mountains by Mr. Traill, of the vici- 
nity of Antrim by Mr. Duffin, the Dungannon district by Mr. Hardman, and that 
of Armagh by Mr. Egan, together with other portions of Westmeath, Longford, and 
Mayo by Messrs. Wilkinson, Cruise, and Leonard. 
hese maps are surveyed on the scale of 6 inches to a mile; and the field maps 
are afterwards reduced and engraved on the Ordnance maps at a scale of one inch 
to a mile, which are published through the agents both in Belfast and Dublin. 
_ These maps are not generally hill-shaded ; but it is intended to publish all the geo- 
logical details of the district, north of a line drawn from Clewe ay on the west to 
Dundalk Bay on the east, on maps having the physical features shown by shading. 
The survey of the Dungannon coal-tield has just been completed, and the results 
are being prepared for publication. This is also true with regard to the Leitrim 
and Roscommon coal-districts, while a fresh survey is being carried out of the 
Leinster coal-field. 
Great pains is also being taken to portray accurately the extent of the deposits 
of iron-ore of co. Antrim, and considerable advance has been made in the survey 
of that district. 
Professor Hull then referred to the Geological Map of Sir R. Griffith, the first 
ever constructed for Ireland, expressing his high appreciation of its beauty and 
accuracy. 
Note on the so-called Crag of Bridlington. 
By J. Gwyn Jerrreys, LL.D., PRS. 
In compliance with a request of the late Professor Phillips, made not long before 
his lamented death, the author examined all the collections of fossil shells from the 
