62 



Tabular view of Fossil Shells from the middle division of the Inferior 

 Oolite in Gloucestershire. By John Lycett, Esq. 



Read 30th July 1850. 



The term middle division of the Inferior Oolite has been adopted 

 from an arrangement of this formation made by Sir R. Murchi- 

 son in 1834, and which, with some slight modification, will be 

 found to be a convenient one for the zoological as well as for the 

 mineral character of the divisions. The following comparison of 

 fossil testacea from the middle division of the formation at Leck- 

 hampton and Crickley Hills with others from a similar geological 

 position near Minchinhampton, and of both collections with 

 Great Oolite shells of the latter place, has been undertaken for 

 the following reasons. The Leckhampton shells constitute a 

 numerous assemblage, have only recently been procured or in- 

 vestigated, and present a striking contrast with those of the 

 upper and lower divisions of the same formation which are well 

 known, and have for the most part hitherto supplied the nume- 

 rous Inferior Oolite fossils to be found in museums and illus- 

 trated works. The person to whom the merit is due of having 

 first drawn attention to this assemblage is undoubtedly Mr. Buck- 

 man, who having procured a few species was immediately struck 

 with the similarity of aspect, and even specific identity, which 

 they presented to certain Great Oolite shells which had previously 

 been believed were peculiar to that formation : as the number of 

 species increased the same general similarity of aspect was re- 

 marked, until at length an opinion was entertained by some of 

 our Cotswold geologists, that a large proportion, perhaps even 

 a majority of these shells, were identical with Great Oolite spe- 

 cies. That the Leckhampton shells should not previously have 

 been procured will excite no surprise, when it is stated that they 

 are not to be picked up, nor do they immediately arrest the eye 

 of the observer like many other Inferior Oolite fossils ; they are 

 usually small, even minute, and are disengaged from the invest- 

 ing stone only by great labour and perseverance. For the means 

 of making this comparison I am indebted to the kindness and 

 liberality of the Rev. P. B. Brodie, who has placed at my dis- 





