382 Reports and Proceedings — 



Barnack Eag beds the little Inferior Oolite Bhjnclionella spinosa, 

 Schloth., lias been obtained. The beds of the Lincolnshire Limestone 

 are surmounted unconformably by certain beds of the Great Oolite 

 series. The lowest of these consists of a very variable clay, often 

 disposed in thin lamin;©, containing sometimes marine and sometimes 

 estuarine or freshwater shells, much wood, and a plant-bed pre- 

 cisely similar to that previously described : it is almost invariably 

 based by a ferruginous band, varying in thickness from six inches 

 to two feet. It has been distinguished as the " Upper Estuarine." 

 The " Great Oolite " Limestone of the district is superimposed 

 upon the clay last named. It consists of a series of variable beds, 

 some very soft, and some crystalline and hard. A band at Alwalton, 

 near Peterborough, takes a good polish, and has been termed 

 " Alwalton Marble." It was used as early as the 13th century for 

 the slender disengaged shafts of the beautiful front of Peterborough 

 Cathedral. Some bands of this limestone abound with fossils, and 

 have yielded, among new forms, two species of a small lobster 

 allied to Eryma elegans, Oppel ; a species of fish, of which only two 

 examples are known (and these both found at Blis worth), Pliolido- 

 pJiorus Fleslieri, Agassiz ; a beautiful small star-fish, having five 

 attenuated and tortuous rays, Opliiurella Griesbacliii, Wright, from 

 Oundle ; a unique fruit, the type of a new genus and species, 

 Kaidacarpum ooliticmn, Carruthers, etc. Over this limestone is 

 frequently found a clay characterized by the abundant presence of 

 the small Ostrea sub-rugulosa, Mor. and Lye. From this clay, in 

 several localities, have been obtained vertebrse of the colossal Cetio- 

 saurus. This clay is in the same sequential position as that at 

 Kirklington, Oxfordshire, whence Professor Phillips obtained the 

 wonderful skeleton of the same Saurian now in the Oxford Museum. 

 It is probably on the same horizon as the Bradford Clay of the West. 

 Above, successively occur the Forest Marble, Cornbrash, and the 

 Oxford Clay, containing the usual fossils ; and the last marking the 

 limit upwards of the range of Secondary formations in the county. 

 The high lands of the district are commonly capped with beds of 

 the Boulder-clay or "Glacial Gravels," having the usual varied 

 contents. The valley-gravels abound with large teeth and tusks of 

 elephants, E. antiquus and E. primigenius, teeth of BMnoceros 

 tichorhimis, bones of Hippopotamus major, teeth of Eqims fossilis, and 

 E. caballus, and heads and horns of Bos primigenius. A peaty fluviatile 

 bed above the gravel contains at its base numerous remains of the 

 small aboriginal ox {Bos longifrons), Ked Deer, Horse, Hog, etc. 

 In describing the geological geograjDhy of the county, the author 

 stated that the ferruginous beds extend throughout the entire area 

 of the county, with the exception of a small portion at its north- 

 eastern extremity ; but they are thickest and probably richest about the 

 middle. The Lincolnshire Limestone occurs only in the Northern 

 division, thinning away near Kettering and Maidwell. The two 

 Estuarine beds are everywhere present when not denuded, coming 

 together after the thinning away of the intervening Lincolnshire 

 Limestone. The Great Oolite Limestone is thickest near Northamp- 



