EAST MIDLAND DISTRICT. 71 



its East Midland character, the section at Hook Norton, read by the light of Mr. 

 Walford's experience, is both interesting and instructive. Between the Upper Lias 

 Clay and the Great Oolite are 31 feet of beds. These are divided into five groups. 

 The lowest group, 4 feet 9 inches, is a sandy blue hearted limestone with corals. It has 

 yielded Bhynchonella cynocephala and some few Gasteropoda characteristic of a low 

 horizon. Since it is by no means easy to separate the Opalinus- from the Murchisonce- 

 zone, this group may be taken as representing the zone or zones usually charac- 

 terised by those two Ammonites. The second group, 10 inches thick, contains an 

 Ammonite-bed ; the species being one of those smooth, flattish forms, similar to 

 the prevailing types in the concavus- or so-called Sowerbyi-beds of Bradford Abbas. 

 Terebratula perovalis likewise is quoted from here. Both the first and second 

 group belong to the Lower Division of the Inferior Oolite. Next comes the usual 

 hiatus, and then the third group, 2 feet 10 inches, has a shell-bed towards the top 

 with undoubted fossils of the Parkins oni-zone ; and in this shell-bed are several 

 species of Gasteropoda. If this group represents the Trigonia-grit, the Gasteropoda 

 lie at the top, instead of at the bottom as in the Aston cutting. The fourth and 

 fifth groups of this section call for no notice here. They are bulky and for the 

 most part devoid of Mollusca, and serve to show the changeable nature of the 

 uppermost beds of the Inferior Oolite hereabouts. 



Details of the East Midland District (No. 3). 



The first fossiliferous beds of Inferior Oolite age in this district which attract 

 our attention are those at Blisworth and round the town of Northampton (Duston, 

 &c), which were regarded by Mr. Sharp as in the zones of Am. opalinus and Am. 

 Murchisonce. I see no reason to doubt Mr. Sharp's determination, the more so as 

 there is a certain degree of resemblance between the Yorkshire Dogger and the 

 Northampton Sand. Cephalopoda are not plentiful, but the Conchifera are large, 

 especially Lima, and fairly numerous. The Gasteropoda are not particularly 

 abundant, nor in a satisfactory condition for determination, occurring principally 

 as impressions in the ironstone. Hence they are not very nice cabinet specimens. 

 It is not probable, therefore, that many, if indeed any, of these specimens will be 

 selected for figuring ; but they will at all times be useful for correlation in those 

 cases where the species can be made out with certainty. The best specimens are 

 in the Sharp collection at the British Museum. At present I am informed by Mr. 

 George and Mr. Beeby Thompson, that it is not easy to obtain many specimens of 

 interest from these beds. 



But the main feature of Inferior Oolite age in the East Midland District is the 

 Lincolnshire Limestone. The chief characteristics of this important series are 



