1853,] MORRIS — LINCOLNSHIRE OOLITES. 339 



a marine bed''', about 4 feet tbick, intercalated with the upper series, 

 but towards the lower part, and separated from the thicker mass 

 of the Great Oolite by the fine plant-bed of Gristhorpe Bay, con- 

 taining Uaio and Estheria. In the strata above the marine bed, zones 

 of bituminous clays can be traced with their associated root-bearing 

 under-beds, similar to those above described in the Railway sections. 

 That these strata are nearly synchronous with the estuary beds at 

 Brora, described by Sir R. Murchison and by Mr. Robertson, and 

 with those in the Isle of Skye described by Prof. E. Forbes, can 

 scarcely admit of doubt, although in both the latter instances the}'' 

 appear to be intercalated between the mass of lower oolites and the 

 Oxfordian series. Two species of Cyrena, however, described by 

 Prof. E. Forbes are identical with species found at Essendine, and 

 the allocation of genera is somewhat similar. 



The above general observations tend to prove that considerable 

 difference of mineral and organic character ol)tained in the Lincoln- 

 shire district, as compared with the south-west of England ; the true 

 Fuller' s-earth rock of Mr. Smith not furnishing a constant or well- 

 marked line of distinction between the Bath Oolite and the Inferior 

 Oolite f, but being replaced by beds having conditions intermediate 

 to and linked with those on the Yorkshire coast, long ago described 

 by Professor Phillips. Instead of the two separate oolite deposits, 

 Great Oolite and Inferior Oolite (as developed in the Cotteswolds), 

 the Lincolnshire Oolite consists of one mass only (as in Yorkshire), 

 between the Cornbrash and the ferruginous rock immediately over- 

 lying the Upper Lias shales, and blending in its fossil contents some 

 of the conditions of the two oolites of the south-west of England. 



In concluding this brief notice of the Lincolnshire sections, I 

 must acknowledge my obligations to Mr. Reynolds and Mr. J. Cubitt 

 for the use of the maps and working sections of this portion of the 

 Great Northern Railway. 



Description of some New Species q/" Mollusca /rojw the 

 Lincolnshire Oolites :f. 



Lima Pontonis, Lycett. Pl. XIV. fig. la, \b. 



Testa convexa, oblique ovata ; auriculis parvis subaequalibus striatis ; mar- 

 gine antico tvuncato excavate et striate ; margine postico rotundo ; cos- 

 tulis radiantibus numerosis (circa 60 ad /O) rotundis, interstitiis confor- 

 mibus, dense et transverse striatis. 



Shell convex, obliquely ovate, auricles small, nearly equal, and stri- 

 ated ; anterior margin truncated, its slope excavated and striated ; 



* See also the paper by Mr. Williamson, Geol. Trans. 2nd Ser. vol. v. p. 324. 



t Geology of Yorkshire, vol. i. p. 130. 



\ I am indebted to my friend Mr. Lycett for the examination and descriptions 



these species. 



VOL. IX. — PART I. 2 A 



