Inferior Oolite in Gloucestershire. 



65 



at Leckhampton, is somewhat di- 

 minished at Stroud, and loses the -2 

 greater portion of its volume, in- « 

 eluding the Oolite marl and all the 

 upper beds before it reaches Bath, 

 where it is represented by 60 feet 

 of freestone. The Bath section is 

 taken from a valuable paper by 

 Mr. Lonsdale in the Geological 

 Transactions. The shells of the 

 middle division are for the most 

 part distributed in beds of no great 

 thickness ; the great mass of the 

 deposit being nearly destitute of 

 organic remains, or containing 

 only minute shelly detritus. 



The numerical results obtained 

 from the Tables of comparison are 

 as follow: — 255 species have been 

 examined from the middle division 

 of the Inferior Oolite, 181 being 

 from Leckhampton, and 145 from 

 Minchinharapton ; of these 73 are 

 common to the two localities and 

 64 pass upwards into the Great 

 Oolite, or 28 per cent. Of the H 

 Leckhampton shells alone 59, i. e. 2 

 33 per cent., and of the Minchin- m 

 hampton Inferior Oolite suite 43, 

 i. e. 31 per cent., pass upwards. 

 Thus, from each of the localities, a 

 larger per-centage of shells pass 

 upwards than is obtained when 

 the entire number of species are 

 reckoned ; an instance of the cau- 

 tious reliance which should be 

 placed upon estimates derived from 

 a limited number of species or 

 from shells of a single locality, 

 where the object is to draw wide 

 and general inferences. It should 

 also be stated that about 40 spe- 

 cies in addition to these were not | 

 sufficiently perfect to be deter- H 

 mined, marly or quite the whole M 

 of which are unknown to the Great g 





J 



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