SCIENTIFIC SUMMARY. 
321 
it to be the Lower Greensand, whose place it occupied. The boring 1 was 
carried further in the hope of reaching the loose water-bearing sands of this 
formation, but the rock became very argillaceous, and, when 62 feet of it 
had been passed through, the boring entered into mottled red, purple, and 
greenish shales, dipping at 35° in an unascertained direction. These beds 
continued through a depth of 80 feet, when, their nature being clearly ascer- 
tained, the boring was stopped. The fossils of these coloured beds, which 
included Spirifera disjunct a, Rhynchonella cuboides, and species of Edmondia, 
Chonetes , and Orthis, show them to be of Devonian age. Thus, the existence 
of Palaeozoic rocks at an accessible depth under London, and the absence of 
the Jurassic series, as maintained long since by Mr. Godwin-Austen, is ex- 
perimentally demonstrated. 
These facts are of interest in connection with the question of the possible 
extension of the Coal-measures under the Cretaceous and Tertiary strata of 
the south-east of England. The beds found at the bottom of Messrs. Meux’s 
boring are of the same character as the Devonian strata which everywhere 
accompany the Coal-measures in Belgium and the north of France, being 
brought into juxta-position with them by great faults and flexures, A re- 
markable section at Auchy-au-Bois, in the western extremity of the Valen- 
ciennes coal-field, is particularly interesting from its furnishing evidence that 
the Hardinghen coal-field, between Calais and Boulogne, is a prolongation 
of that of Valenciennes, and because the same strike and a prolongation of 
the same great fault observed at Auchy-au-Bois through Hardinghen would 
carry the southern boundary of any coal-field in the south-east of England 
just south of Maidstone, thence passing a little north of London. Hence it 
is in the district north of London that there is most probability of the dis- 
covery of the Carboniferous strata. The extent of country in which shafts 
could be sunk to the Palaeozoic strata will, however, be limited by the 
presence of the water-bearing Lower Greensand, which probably reaches 
close to London in the south, reappears in Buckinghamshire and Bedford- 
shire, 30 or 40 miles north of London, and probably extends some distance 
towards the city under the Chalk hills of those counties and Hertfordshire. 
The nature of the representative of the Lower Greensand in the boring, 
and the characters of the fossils contained in it, lead to the conclusion that 
in it we have a deposit produced near the shore of the Neocomian sea, here 
probably consisting of cliffs of Devonian (or Carboniferous) rock. From 
these cliffs the calcareous material which here replaces the usual loose sands 
of the Lower Greensand was perhaps derived by the agency of springs j and 
the shore-line itself must be situated between the south end of Tottenham 
Court Road and the Kentish Town boring. The sandy beds of the Lower 
Greensand will probably be found to set in at no great distance to the south- 
ward, presenting the conditions necessary for storing and transmitting under- 
ground waters. A test boring made by Mr. H. Bingham Mildmay at 
Shoreham Place, about five miles from Sevenoaks, and in which the Lower 
Greensand was met with at about the estimated depth (450 feet) and 
furnished a supply of water, seems to confirm these views. 
A Fossil Passerine Bird from Colorado. — The wonderful insect-bearing 
deposits of Florissant, Colorado, have furnished the remains of a Passerine 
bird, the first of its type that has yet occurred on the American continent. 
NEW SERIES, YOL. II. — NO. VII. Y 
