THE ANNALS 



AND 



MAGAZINE OF NATURAL HLSTOUY. 



No. 50. NOVEMBER 1841. 



XIX. — Description of some new Species of Ammonites found in 

 the Oxford Clay on the line of the Great Western Railway 

 near Christian Malf or d. By Samuel Peace Pratt, Esq., 

 F.L.S., F.G.S. 



[With Four Plates.] 



The cuttings for the Great Western Railway between Chip- 

 penham and Wootton Basset having been almost entirely in 

 the Oxford clay, and having exposed nearly the whole of that 

 deposit, numerous fossil remains have been discovered, inclu- 

 ding many new species. The Oxford clay, in this neighboui'- 

 hood, forms three distinct beds, viz, the upper and lower blue 

 clays, separated by the ferruginous Kelloway rock ; and each 

 division has its distinct fossils, although several species are 

 common to each of the three divisions. Besides the undescribed 

 species, many have been found throughout the series which 

 had hitherto been considered as characteristic of either higher 

 or much lower beds ; thus Ostrea deltoidea and Gryphcea vir- 

 gula are numerous in both the upper and lower beds, though 

 formerly considered to be confined to the Kimmeridge clay; 

 and several shells belonging to the inferior oolite, as Astarte 

 modiolaris and Lima prohoscidea, with some others, are found 

 in the upper beds near Wootton Basset. In the neighbour- 

 hood of Christian Malford, about four miles from Chippen- 

 ham, the site of the Kelloway rock appears to be represented 

 by a bed of gravel a few feet in thickness, which, besides the 

 usual fossils of that bed, contains also numerous rolled spe- 

 cimens from the neighbouring hills of coral rag and calca- 

 reous grit. Bones of tiie Elephant and other mammalia have 

 also been found in it. Beyond the gravel to the N.W., in the 

 direction of the rise of the strata, the clay assumes a slaty 

 character, and contains numerous fossils, chiefly peculiar to 

 the spot, such as ten or twelve species of Ammonites, more 

 than half of which are undescribed, several species of Belem- 

 nites, Sepiae, Fishes, and numerous shells, which although 

 much compressed are beautifully perfect. 



The Ammonites are remarkable for having the aperture in 

 Ann. (5)- Mag. N. Hist. Vol. viii. M 



