12 
Messrs. Sollas and Jukes-Browne, in their paper ‘‘On the 
included rock-fragments of the Cambridge Upper Green sand,” 
state they are of different lithological characters, and derived from 
Paleozoic formations ; among the most abundant are mica-schists, 
basalts, granites, felspathic shales, vein-quartz and coarse grits ; 
and we may refer them to gneissic, volcanic, schistose, and 
sedimentary rocks, probably of Old Red Sandstone, and Car- 
boniferous age. Many of the fragments are incrusted with 
coprolite, Hxogyra, Spondylus truncatulus, Plicatula sigillum and 
Ostrea vesiculosa.* 
Prof. Ehrenberg + many years since pointed out the identity of 
certain living forms: of Foraminifera with those of the Cretaceous 
epoch, and which were noticed by Mr. Lonsdale,{ Dr. Mantell,§ 
Prof. Bailey and the later and more extended investigations of other 
observers, Prof. Huxley, Count Pourtales, Dr. W. B. Carpenter, 
and Prof. Wyville Thompson. 
The resemblance of the fauna and character of the Atlantie Bed 
has led the latter of the above naturalists to conclude that ‘‘ we are 
still living in the Chalk period,” a statement in which the late Sir 
C. Lyell ** did not, and Prof. Prestwich ++ and Prof. T. R. Jones {f 
do not fully coincide. It is true that we find, as before noticed, 
both cretaceous and living, about 20 species of Foraminifere, 
some closely allied sponges, a coral Caryophyllia cylindracea,§§ five 
or six genera of Echinodermata, about 80 genera of Mollusca, 
probably two species of Brachiopoda, and species of Beryx; but 
the characteristic cretaceous forms are wanting, such .as_ the 
Belemnitida and Ammonitide (the Nautilus being the only tetra- 
branchiate now living), the Lamellibranchiate Inoceramide and 
Hippuritide, the Gasteropodous Neringa and the extinct Lacertilia 
(Mosasaurus, Polyptychodon, &c.), and the orders Pterosauria and 
Enaliosauria. 
The chalk period terminated, and with it became extinct its 
characteristic fauna, brought about, probably, by a great change in 
the physical geography of the area, by elevation of the sea-bed, 
or shrinking of the sea, which preceded the commencement of the 
Tertiary era, and which, in this vicinity, presents so marked a change, 
the phosphate-bed may be matched from Charnwood); and we might look to the Trias, 
which on every side of Charnwood abuts upon the Cambrian rocks, to have furnished the 
ochreous deposit giving rise to the Red Chalk.”—Quart. Journ. Geol. Soc., vol. xxix., p. 62 
* Quart. Journ. Geol. Soc., vol. xxix., p. 11. 
+ See Ann. and Mag. Nat, Hist., 1841, vol. vii., p. 296. 
t Lyell, Ann. Address, Proc. Geol. Soc., vol. ii., p. 365. 
§ Wonders of Geology, 1857, p. 305. 
** Elements of Geology, 2nd ed., p. 272. 
t+ Anniversary Address, Quart. Journ. Geol. Soc., vol. xxvii., p. 69. 
tt Ann. and Mag. Nat. Hist., 1872, vol. iv., p. 295. 
§§ Duncan, Quart. Journ. Geol. Soc., vol. xxvii., p, 434. 
