Age of "' the Dingle Beds " and " Glengariff Grits:' 369 



having also carefully examined the field-maps of the Survey of 

 those districts, had arrived at the following results : — 



First, that " the Dingle Beds " are perfectly conformable to, and 

 continuous with, the Upper Silurian Beds of the Dingle promontory. 



Secondly, that they are the representatives of "the Mweelrea 

 Beds and Salrock Slates " of "West Galway and Mayo, the age of 

 which, as shown by the fossils, is Upper Silurian, and that "the 

 Dingle Beds " may therefore be regarded as of the age of the Ludlow 

 Hocks, but unusually developed. This view was adopted as far back 

 as 1839 by Sir Richard Griffith. 



Thirdly, that throughout the south of Ireland " the Dingle and 

 Glengariff Beds " are disconnected from the succeeding conformable 

 series, consisting of (c) Lower Carboniferous Slate, (b) The Upper 

 Old Red Sandstone with Anodonta JuJcesii, (a) The Lower Old 

 Red Sandstones and Conglomerate, as these three conformable 

 formations are found resting upon, and against, the Glengariff beds 

 successively in a direction either from south to north, or from 

 south-west to north-east, owing to a conformable overlap against 

 the flanks of an old shelving shore formed of the Glengariff beds. 



Fourthly, that at the close of the Upper-Silurian period, and 

 after the deposition of "the Dingle and Glengariff Beds," these 

 strata were disturbed, upraised, and denuded, and were uot again 

 submerged till the commencement of the Old Red Sandstone (a), 

 when they were successively overlain by the beds of that formation 

 with the succeeding ones of the Lower Carboniferous period, pro- 

 bably including the Carboniferous Limestone in some places. 



Lastly, that it was during this period of upheaval that, as the 

 author believes, the marine Devonian Beds (Ilfracombe and Morte 

 series) were deposited, which accounts for their absence in the 

 Irish area, which was either a land surface or only partially sub- 

 merged. To this part of the subject the author hoped to call the 

 attention of the Society on a future occasion. 



2. " On some Three-toed Footprints from the Triassic Conglo- 

 merate of South Wales." By W. J. Sollas, Esq., M.A., F.G.S. 



The author described the discovery by Mr. T. H. Thomas of 

 some three-toed footprints in the Triassic Conglomerate at Newton 

 Nottage, South Wales. They were stated to resemble in their most 

 important characters the footprints of some Ratite birds, such as 

 the Emu ; and this fact, taken in connexion with the occurrence 

 of Dinosaurian remains in the Magnesian Conglomerate of Bristol, 

 led the author to attribute to them a Dinosaurian origin. 



3. "On the Silurian District of Rhymney and Pen-y-lan, Cardiff." 

 By W. J. Sollas, Esq., M.A., F.G.S. 



The paper commences with a history of the previous observations 

 on the district ; a description of the geographical distribution, geo- 

 logical structure, and vertical succession of the Silurian rocks is next 

 given. They comprise beds belonging to the Wenlock and Ludlow 

 groups, and pass conformably upwards into the Old Red Sandstone . 

 The district affords a good base for a measurement of the thickness of 



