NOTES AND CORRECTIONS. 



Fossils fyured in the former parts of this Monograph from the Coast of Yorkshire, and 



attributed to the Great Oolite. 



IT may now be stated, as the general conviction of Palaeontologists who have critically studied the 

 subject, that the Testacea of all the marine beds intercalated with the important but local plant-bearing 

 shales and sandstones of the Yorkshire coast, intermediate the Cornbrash and the Dogger, constitute an 

 Inferior Oolite fauna, but that the mineral character of these deposits and their sequence are peculiar to the 

 locality ; it is found also, as might be expected in deposits so isolated in their general conditions, that the 

 fauna of these several marine beds, although undoubtedly pertaining to the Inferior Oolite, cannot be 

 arranged with precision upon any corresponding horizons of the same formation, either in Britain or upon 

 the Continent. But in discarding the correlative value of the minor subdivisions, it appears that they may 

 be assigned approximately to those groups of beds which constitute the upper portion of the Inferior 

 Oolite, and which have been divided by Quenstedt, Oppel, and others, into two distinct stages, the lower of 

 which is characterised by the presence of Ammonites Humphriesianus, the upper by Ammonites Parkinsoni. 

 Upon the coast of Yorkshire these Ammonites, however, have occurred in the same bed, and the number of 

 marine floors is so few that they cannot be considered as representing the two superior stages in the 

 entity of their mass and of their fauna ; their deficiencies are more especially remarkable in the rarity of 

 the Brachiopoda and of the Ammonites. 



These conclusions have been arrived at by an investigation of a series of details so extensive and 

 decisive in their results as to admit of no uncertainty upon the subject. That the marine beds in question 

 should have been assigned to the Great Oolite upwards of thirty years since by the author of the ' Geology 

 of Yorkshire ' will not excite surprise in any one who is able to recall to memory the rudimentary condition 

 of Palaeontology at that period, and the absolute ignorance which then prevailed of the Testacea of the 

 Great Oolite ; that the Paloeontology of the Jurassic portion of the work in question constituted a great 

 advance upon the previous work of Messrs. Young and Bird was at once recognised, and the author candidly 

 stated that he assigned these marine intercalated beds to the Great Oolite solely from their position higher 

 than certain beds of undoubted Inferior Oolite, and lower than the Cornbrash. The progress of knowledge 

 tending to arrange them with the Inferior Oolite, was gradual. Following the work of Professor Phillips, in 

 1839 appeared the two well-known memoirs of Professor Williamson on the distribution of organic remains 

 in the Oolitic rocks of Yorkshire, in which the subordinate beds of the Lower Oolites and their organic 



