214 



Abingdon and Marcham, Berks ; Weymouth, Dorset ; &c. The 

 following are the leading fossils I have collected from the first 

 of these localities : — 



Cephalopoda. 



Anmiomtes perannatus, Sow. Ammonites Lamberti, Sow. 



" cordatus, Soio. « Arduennensis, d'Orh. 



" SutherlandisB, Sow. « crenatus, Brug. 



Without making a special study of the Calcareous Grit it 

 would be impossible to give a correct table of its conchifera, 

 as our lists have for the most part been made fi-om the Coral rag 

 and Calcareous Grit taken together. Although the Ammonites 

 I have named are found in the upper part of the Oxfordian, 

 still I think that portion of the bed more properly belongs 

 to the zone of Am. perarmatus, than to the slaty bituminous 

 shales of the true Oxford Clay on which it rests. 



CoEALLiEN = Coralline Oolite. 



The Corallien in the Cote-d'Or consists, according to M. 

 Martin, of the following sub-divisions : — 



A. Oolitlie corallienne a Diceras et calcaire compacte. 



B. Calcaii-e fissile sub-oolithique et calcaii-e blanc a Polypiers. 



C. Calcaii-e grujneleux compacte, calcaire a chailles et mames 



inferieures a Glypticus hierogliphicus, Cidaris florigemma, &c. 



The Coral Eag and Pisolite of Dr. William Smith is, in part 

 only, the equivalent of this stage, which is so well developed in 

 Wiltshire, Berkshire, Oxfordshire, Buckinghamshire, Dorsetshire, 

 and Yorkshire, and forms such an important feature in the 

 sedimentation of the Middle Oolites. During the Oxfordian 

 age. Ammonites, numerous in species and multitudinous in 

 individuals, crowded the seas from which were deposited the 

 middle Jurassic formations from the macrocephalus to the 

 perarmatus zones of life ; but with the commencement of the 

 coralline stage, on the study of which we now enter, a great 

 change in the physical conditions of the bed of that sea seems 

 to have taken place; the comparative shallow water in which 

 the Oxfordian Cephalopoda disported, was now changed into 



