264 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 5, 



and others in similar beds at Banthorpe, Essendine, and near Peter- 

 boro'. 



Large specimens of Ammonites gracilis, Buckm., occur in the 

 Northampton beds ; I have a less large example from Stamford. 



Natica formosa, JV. intermedia, and other species of Natica having 

 elevated spines, occur in great numbers at Kingsthorpe and Blis- 

 worth ; they are prevalent forms also at Belmisthorpe, Essendine, 

 and Danes' Hill. 



Pholadomya (deltoidea, Heraulti, lyrata, socialis, &c.) is a most 

 abundant genus in the Northampton beds : it is as abundant and 

 various at Belmisthorpe, and also occurs at Essendine and Danes' 

 Hill. 



Modiola imbricata is equally numerous in the beds of both dis- 

 tricts, as are also Myacites calceiformis, Cypricardia Loweana, and 

 Isocardia tenera. 



Terebratula maxillata and JRhynchonella concinna, such marked 

 forms at Blisworth and Kingsthorpe, distinguish also Danes' Hill and 

 Essendine. 



Other forms, of less abundance but of much significance, are 

 common to the beds which I have termed " Great Oolite " in both 

 localities ; such as the rare Amberleya nodosa of Mor. & Lye, the 

 still more rare Necera Ibbetsoni (known only, I believe, in the Great 

 Oolite beds of these localities), and the beautiful undesciibed crus- 

 tacean allied to Eryma elegans of Oppel, so abundant at Buttock's 

 Booth near Kingsthorpe, and also found at Belmisthorpe, Essendine, 

 and Danes' Hill. 



Besides these, are the abundant and puzzling series of shell-less 

 fossils, so difficult of recognition ; and which the great experience 

 and persistent patience of Mr. Etheridge alone enabled him approxi- 

 mately to identify. Among these, are Ceromya Symondsii, Cypri- 

 cardia Bathonica, Cardium Buckmani, Unicardium, and others ; the 

 similarity of which, both as to condition and form, in the groups 

 obtained from the two localities, also serves to mark the parallelism 

 of the beds whence they have been derived. 



Little Bytham. 



At Little Bytham, two miles north of Danes' Hill, the Great 

 Oolite Limestone has disappeared ; but the Upper Estuarine Clays 

 exhibit a thickness of about 30 feet, and the ferruginous band at 

 the base is still present, as it is in several other cuttings further 

 north. Below the Clays, the Lincolnshire Limestone appears in the 

 form of good oolitic freestone ; and this (for the sake of the stone) 

 was excavated, during the making of the railway, to a considerable 

 depth below the floor of the cutting. Under 10 feet of this free- 

 stone, was found a compact marly limestone, 3 feet in thickness ; 

 and beneath this again, 8 feet of good freestone. 



The Pontons. 

 Four miles south of Grantham, is the Great Ponton cutting. 

 Under about 6 feet of the Upper Estuarine Clays, are 37 feet of the 



