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of their structure in the enveloping chalk, points to the conclusion 

 that the period in which the flints were formed must have been 

 previous to that consolidation of the mass of the chalk by which 

 the smaller fossils were mostly destroyed." It may not be un- 

 interesting to note that in the flint meal (about two pounds in 

 weight) of this one nodule, Dr. Hinde found 160 different forms 

 of spicules which he divided among 38 species and 32 genera of 

 sponges. Besides these there were fossilized remains, entire or 

 fragmentary, of Foraminif era, Echinoderms, Annelids, Cirrepedia, 

 Ostracoda, Polyzoa, Brachiopoda, Lamellibranchiata, and lastly 

 Fishes (p. 6, op. cit.) 



It was evidently a portion of the ooze of the cretaceous ocean 

 which had thus been enclosed in this siliceous envelope and so 

 preserved to us. 



The chalk itself, though bearing much analogy with the 

 globigerina ooze of the Atlantic, must have been deposited under 

 somewhat different conditions, and much more rapidly thau that 

 is at present being formed. The fragile arms of the Cidaridte are 

 still in their natural position, the scales of the fossil fish are still 

 undisturbed and undecayed. 



Was the Formation of the Flints Strictly Contempoeaneous 

 WITH that of the Chalk ? 

 The argument for the contemporaneity of the chalk and flints 

 is well put by Dr. Wallich in his paper on " The History of 

 Cretaceous Flints" (Journal of the G-eological Society, vol. 36). 

 Dr. Wallisb sees on the floor of the Cretaceous ocean the ooze 

 interpenetrated with fibres and spicules of sponges, and also 

 with the sarcode or protoplasm, as at present obtains over wide 

 areas of the bed of the Atlantic. This protoplasm enters into 

 combination with the silica, and the first step is thus taken 

 towards a layer of nodules. Then a period ensues during which 

 the Foraminif era are in the ascendant and their accumulated 

 calcareous tests go to form the pure white chalk. After a time 

 there is again an exuberant growth of siliceous organisms. 

 Hence the intermittent layers of flint. But there is too much here 

 purely speculative, too much taken for granted, and the balance of 

 authoritative opinion is certainly against such a hypothesis. Most 

 geologists consider that these siliceous nodules must have been 

 formed while the chalk was still beneath the water, though 

 perhaps some way beneath the actual floor of the sea. Here the 

 chalk would be still in a more or less mobile and plastic state. 

 Such a condition would allow to all its constituents a certain 



