THE 'DERIVED' FOSSILS. 45 



There was no Oxford clay exposed within some few miles of 

 Up ware, but yet the little Ammonites there are perfectly well 

 preserved. 



General. From the presence of these remanie materials of 

 Oxfordian to Neocoinian ages inclusive and from the nature of the 

 rock, it is clear that the Upware and Brickhill deposits were formed 

 along the neighbourhood of a shore whose coast consisted of the 

 upper and middle Jurassic rocks. In pre-cretaceous times the 

 Kimmeridgian and probably the Portlandian rocks extended from 

 Dorsetshire to Yorkshire, and the Purbeck and Wealden conditions 

 also had a greater spread than now, probably reaching as far as 

 Potton if not to Upware. The old coast line ran from S.W. to N.E. 

 along a line to the west of Calne, Warminster, Farringdon, Oxford, 

 Potton and Cambridge to our present Wash, and thence trending 

 N.W. ran up into Yorkshire. 



The following lists include all the derived species known to 

 me from Upware and Brickhill. 



I. THE 'DERIVED' FOSSILS OF THE UPWARE DEPOSIT. 



Belemnites, Phragmicoe of Nerincea. 



abbreviates, Miller. Aporrhais. 



explanatus, Phill. Turritella or C/wmnitzia. 



Nautilus, sp. Exogyra (Coral Rao;). 



Ammonites biplex, Sby. Gryphea dilatata, Sby. var. Coral 



,, cordatus, var. Marice, Rag, &c. 



d'Orb. Ostrea gregaria, Sby., Coral Rag. 



Ammonites biplex, d'Orb., of the Lithodomus inclusus, Phill., Coral 



Oxford clay. Rag. 



Ammonites Deshayesii, Leyra. Modiola, sp. 



small smooth species Perna Mulletti (in dark grit). 

 (? Neocomian). Ricordiana, d'Orb. 



Ammonites Kcenigi, Sby. (collection Pecten vimineus, Sby., Coral Rag. 



J. F. Walker, M.A.). Unicardium, Coral Rag. 



Ancyloceras, sp. (J. F. W.). Opis Corattina, Coral Rag. 



sp. in gritty phosphate. Pectunculus, ribbed species, in 



JIa mites. phosphate. 



Chemnitzia Heddingtonensis, Sby. Trigonia incurva, Sby. ? 

 Cerithium muricatum, Sby. gibbosa, Sby. ? 



Litorina (in dark grit). Cardium striatulum, Sby. 

 Cerithium (ditto). dissimile, Sby. 



Pleurotomaria reticulata, Sby. Lucina Portlandica, Sby. 



,, sp. Cyprina, large species. 



? Buccinum naticoides, Sby. Myacites, of Portland oolite, and 

 Natica, 2 sp. Kimmeridge clay. 



