260 T. Davidson — Continental Geology. 



the Albien or Gault of Folkestone," by Mr. C. E. de Eance, will be 

 found in the Geol. Mag, for 1868, and we may obtain considerable 

 fresh light upon the Gault from the careful and indefatigable labours 

 of the Eev. T. Wiltshire in that same locality and formation. Indeed, 

 many points of considerable interest still remain to be determined 

 with reference to our Cretaceous system ; and it was with the hope 

 of stimulating further research that I have been led to offer in the 

 pages of this Magazine the opinions entertained by foreign geologists. 

 Having now given the views of most of the French and Swiss 

 geologists with reference to the subject at issue, it will be desirable 

 to cast a rapid glance at the position of matters in the North of 

 Germany, where the Cretaceous system attains an important de- 

 velopment. I have, therefore, requested the eminent geologist, 

 Herren A. Von Strombeck, to forward me his most recent views, 

 which he has kindly done in the shape of the following table. He 

 informs me likewise by letter that the succession of beds which he 

 transmits is not dubious, and has remained the same for a long 

 period in all his memoirs. It is only the grouping and the com- 

 parisons that have undergone changes, and that the identification of 

 a large proportion of the fossils (especially of the Brachiopoda) 

 which he has published, at various periods, will require revision, 

 consequently he has not introduced into his table the names of 

 characteristic fossils, but, as a compensation, he includes the locali- 

 ties.^ He also adds that in the Lower Chalk they have in Germany 

 two levels or horizons which are entirely similar in other regions, 

 that is to say, the Calcareous Clay with Amm. Nisus (Marls of 

 Gargas), and the zone with Toxaster complanatus ( = Marls of 

 Hauterive). M. Strombeck infers that the Lower Green Sand of 

 England is not the equivalent of the true Neocomien, but of the 

 German zone with Ostrea aquila, which are rather more recent. It 



are often waterwom ; you seldom find associated bones of reptiles, sometimes tlie rep- 

 tile bones are broken and oysters are deposited on tbe fractured sm-faces. 4th. The 

 fossils are nearly always covered with the phosphate deposit, oysters are attached to 

 the nodules ; the nodules are rolled, appear to have been brittle, as I have found 

 pieces broken, and the characteristic Plicatula attached to the broTcen surface, which 

 would tend to prove that they had not been formed where they are found. 6th. The 

 bed is thin, full of nodules, bones and shells ; the green grains pass up into the Chalk, 

 above the nodule bed, the clay below contains very few fossils (I have obtained fiish 

 vertebrae and Plicatula pectioioides). Now if the sea coast had consisted of Gault Clay, 

 which was destroyed by the sea, the nodules, bones, shells, might be washed out 

 (as the denudation of the drift clay forms beds of gravel) and form the Cambridge bed. 

 This would give the reason for the mass of nodules, etc., accumulated in so small 

 a space; some of the bones need not have rolled for a long time, but might be 

 carried by currents into deep water, then we might get associated bones. 6th. It is 

 possible that T. gracilis and some others may be of the age of the deposit, and may be 

 found at the base of the Chalk. Bones that have not been through the washing 

 mills are often waterworn, the mills used to be blamed for the appearance of 

 the fossils. 



^ Mr. Judd is happy to be able to bear his testimony to the relations of the beds 

 which M. Von Strombeck has made with so much skill and labour. "When in 

 Germany he saw most of the beds which he refers to in his table, many of them 

 under his own guidance ; but as there is no good general section in Brunswick, 

 and detached stone pits, brick yards, etc., form the only means of study, he believes 

 that considerable changes may still have to be made in the grouping of the beds. 



