448 Prof. Harkness's Address to Section C. 



Duston, within a distance of a mile and a half, they present a 

 section of 25 feet. They here consist of a dark red brown rock, 

 having a cellular texture (the walls of rich iron ore enclosing 

 ochreous cores), and are disposed in some seven or eight beds, from 

 three to five feet in thickness, divided by joints and fissures, and 

 traversed by shelly and coral zones, and a plant-bed. Near the 

 top is a zone crowded with Astarte elegans, associated with 

 which occur patches of Astarte minima ; this zone is persistent over 

 a considerable area, and is useful in determining at other points the 

 general sequence and position of certain beds. The fossils are 

 generally characteristic Inferior Oolite forms ; but with them is 

 found Plioladomya ambigua (?) and from near the bottom of the series 

 have been obtained, from widely -separated localities, two well-defined 

 examples of Ammordtes bifrons. This leads me to conjecture that, 

 in the lowest portion of the Ironstone-beds of the Northampton 

 Sand, we have a passage-bed from the Upper Lias to the Inferior 

 Oolite, representing, perhaps, the Cephalopoda-bed of the Cotswold 

 HiUs and the sands below. The Pal^ontological evidence, I think, 

 proves conclusively that the Northamptonshire ironstone (all below 

 the coarse shelly limestone No. 5, and the slate-bed No. 6, and 

 including these beds, down to the Upper Lias Clay) is Inferior 

 Oolite. 



A study of these Northamptonshire beds reveals the interesting 

 phenomena of repeated alternations, during their deposit, of marine 

 and estuarine conditions. I think it probable that a careful ex- 

 amination of the several strata over a large area might determine 

 the character and direction of each estuary. Indeed, from the 

 relative localities of the thickening and thinning of the ironstone- 

 beds, I have an impression that the estuary which they represent 

 had a direction north-east to south-west. 



Dallington Hall, Northampton, 

 Aug. 19, 1869. 



n^OTiciES OIF :vnEDvnoii2/S. 



British Association for the Advancement of Science, Exeter, 

 August, 19th, 1869. 



SECTION C — GEOLOGY. 



Address by Professor Egbert Harkness, F.R.S.. F.G.S. (of Queen's College, 

 Cork), President of Section C. 



IT has of late become the custom to open the several Sections of the 

 British Association with an introductory address. This custom 

 had, I believe, its origin in this Section when the Association met at 

 Aberdeen ; and upon that occasion Sir Charles Lyell made the 

 important discovery of the late M. Boucher de Perthes, of the 

 occurrence of flint weapons with the bones of extinct mammalia in 

 the gravels of the Valley of the Somme, the subject of his opening 

 address. In some instances new matter of importance in connection 

 with geology has furnished materials for the opening address ; but 



