72 GASTEROPODA OF THE INFERIOR OOLITE. 
given in ‘ Judd’s Geology of Rutland,’ and more recently in another Survey Memoir 
by Messrs. Jukes-Browne and Dalton. So extensive is this subject, that I may well 
be excused for not entering into particulars in an “ Introduction to the Inferior 
Oolite Gasteropoda.” As regards the position of the Lincolnshire Limestone in the 
geological scale, it. has generally been referred to the Sowerbyi- subzone. But I 
am disposed to think that the greater portion of it belongs to the upper part of the 
Murchisone-zone. This would bring it on the level of the Oolite Marl of the 
Cotteswolds, simply as regards geological time. I think that there can be little 
doubt, from the abundance of Nerinwa Cotteswoldie in the compact limestones of so 
many localities, that such beds are on the horizon of the Oolite Marl, or just a 
little below, whilst the abundance of casts of Natica cincta (Leckhamptonensis) seem 
to point to the Oolite Marl itself. But it is apparently above these beds where 
we find that finely oolitic and broken shell-rock which swarms—though only at rare 
intervals—with Gasteropoda. Unfortunately they are much rolled, but now and 
then some really good specimens are obtained. Though the prevailing forms are 
decidedly small in these beds, yet some shells, especially those of Nerinwa, attain a 
considerable size. 
By far the richest exposure of this class of beds is at Great Wuipon, four and 
a half miles south-south-east of Rockingham, in Northamptonshire. Asa section it 
is of no value, being a mere roadside opening near the village, about 8 feet in depth. 
The uppermost 4 feet consist of a shivery or platy kind of rock, with numerous 
small Oysters on the bedding planes. The lower half is a comminuted shell and oolite 
rock, and it is on the top of this that the richest accumulation of small Gasteropods 
may be noticed. A few hundred weights of well selected stuff will afford employment 
to the fossil hunter during many a winter’s day. Innumerable small Cerithia of the 
limeforma group, some of them identical with C. Beanii of the Yorkshire Beds, 
are probably the most‘characteristic fossils. Monodonta levigata, usually the typical 
form, but rather smaller than Dundry specimens, is on every block, and small 
species of T'rochus, &c., are very numerous. The largest shells I have met with are 
the so-called ‘* Phasianellas,’’ which seem to occupy the place of Natica, here almost 
entirely unrepresented. The curious shell Cloughtonia cincta occurs here, and also 
at Ponton, but is rare. This constitutes another link with the Yorkshire Beds. I 
am not aware of its ever having been detected further south. 
Another exposure is at Wansrorp, about eight miles west of Peterborough. 
This was more famous in former days, and is probably the locality “near Peter- 
borough” of the Sharp collection. The Northampton collectors have obtained 
some good things from here, but the section is for the most part grass grown, and 
fine fossils are scarce. 
The next best place is the railway cutting at Great Poynton. The depth of the 
cutting is about 20 feet. The beds which contain the Gasteropoda are very limited 
