Mr. J. F. Walker on a Phosphatic Deposit. 381 
rison of specimens; and the sutural space of the Australian 
species is never so deep or concave as in its European prototype, 
in which also the plaits on the columella are very much less 
conspicuous and more oblique, the anterior one alone approach- 
ing the size of the four on V. anticingulatum. The spire has 
one sculptured whorl, fuller than in the V. cingulata of Ger- 
many. ‘There is no living species like it. 
Very abundant, with occasionally the @ variety and more 
rarely the a variety. ee in the Tertiary sands of the 
Bird Rock beds, Ad. 22 to 21, less so in Ad. 23. Both varieties 
common in the sandy beds Ad. 24. 
XLVIII.—On a Phosphatic Deposit in the Lower Greensand of 
Bedfordshire. By J. F. Waker, F.C.S., Sid. Suss. College, 
Cambridge*. 
[Plate XIII. ] 
Tuer Lower Greensand formation in Bedfordshire consists of 
extensive beds of variously coloured sands, more or less indu- 
rated into stone. 
In the vicinity of Sandy there exists a conglomerate which it 
is proposed to discuss in this paper. A short account of this bed, 
by the Rev. P. B. Brodie, appeared in the ‘ Geological Magazine’ 
for April. I sent a short paper on the discovery of some fossils 
in it to the ‘Annals and Magazine of Natural History’ for July; 
Mr. H. Seeley this month (August) also communicated his views 
on this bed in a letter to the Editors of that Magazine. 
This conglomerate was formerly quarried for mending the 
roads, until ‘two or three years since, when it was discovered that 
it contained nodules of phosphatic matter, for which it is at pre- 
sent extensively worked. Ata cutting near the Potton Railway 
station the bed is from 9 inches to | foot in thickness; and the 
following is the section, the strata-here being slightly inclined. 
1. Sand of different colours, in some places white. 
2. Conglomerate bed, 9 inches to 1 foot in thickness. 
3. Sand of various colours, containing layers of oxide of iron, 12 feet. 
* Communicated by the Author, having been read before the British 
Association, in Sections B. and C., at Nottingham, 1866. 
