On the Phosphoric Strata of the Chalk Formation. 
65 
externally of a green colour, and of all sizes from a hiizcl-nut to an 
ordinary potato. ... Some beds of green-sand occur near the junc- 
tion, and others at the bottom of the gault, and near its junction with 
the iron-sand. Its organic remains seem to identify the gault with the 
clay at Folkstone." There can be but little doubt from this description 
that the fossil-beds both of the upper and lower green-sand occur in 
these neighbourhoods. 
Dr. Fitton ii> his memoir on the strata below the chalk gives several 
sections of the subsoils, the members of some of which, from the de- 
scription given of the colour and organic remains, appear to be identical 
witii the phosphoric green marl. The following pages seem to indicate 
these beds : viz., at 234, giving a section at Whitecliff, near Bere, in 
Devonshire; 247, a section of Ridge, inWdtshire; 2o7, where special 
reference is made to the similarity of the marl rock to that at Farnham, 
in Surrey ; 305 and 306, where mention is made of the persistent thin 
band of green marl; 311, a section at MilJenhall, in SuHblk ; 314, a 
section at Hunstanton, in Norfolk. 
Dr. Mantell also, in the ' Geology of the South-East of England,' at 
pages 160 to 164, particularizes this band of green marl, with its charac- 
teristic fossils, as being traceable along the talus of the northern s;de of 
the South Downs. 
Professor Henslnw, at the meeting of the British Association held at 
Cambridge in 1845, stated that "a stratum of green-sand, although 
never more than a foot thick, occurred near the surface over many 
square miles in the vicinity of Cambridge ; and the pebbles it contained 
yielded 61 per cent, of earthy phosphates and 24 carbonate of lime, the 
rest bemg insoluble." These pebbles were at that time considered to 
be coprolitic by Professor Henslow ; but subsequently he has seen reason 
to modify his opinion, and does not consider these remains or those of 
the Suffolk fossils to be of coprolitic origin. 
In a letter published in the Bury Pose newsjiaper soon after the meet- 
ing of the British Association at Cambridge, Professor Henslow enters 
more fully into particulars relative to the fossils of this deposit, as well 
as to those of the crag in Essex and Sutfolk : the extensive supply of the 
latter phosphatic concretions has already been adverted to in the former 
part of this paper. With respect to the nodules found in the green marl 
bed, he says that they are often filled with fossil remains, sometimes the 
mere casts of shells. The fossils and nodules are so manifestly of the 
same composition, that whoever saw them together would not doubt it ; 
and with regard to the quantities likely to be obtained for agricultural 
purposes, he states that " his own opinion is decidedly in favour of their 
being sufficiently abundant to make it worth while to collect them." 
A communication on the same subject was made by Professor Henslow 
to the Geological Section of the British Association at Oxford last year, 
but as the official reports of the meeting are not yet published, further 
notice of it in this place is unuecessarv. 
To Professor Henslow, therefore, is most willingly conceded the 
merit of having first brought before the public the fact of the existence 
of a stratum containing organic remains in the upper green-saud re- 
markably rich in phosphate of lime, which he considered might be found 
VOL. IX. F 
