1870.} SHARP—NORTHAMPTONSHIRE OOLITES. 361 
Among the points of interest in this section are :— 
1. The “ Dirt Bed” (no. 3), which is of very similar character to 
the “shaly”’ bed at Tinkler’s pit at Stamford, noticed by Professor 
Morris in the typical section of the Stamford Oolites given in a note 
in his paper in the Journal for November 1853. This bed is evi- 
dence of a comparatively brief but marked change in the local con- 
ditions during the period of its deposit. 
2. The “ Paving Beds” (nos. ’7 & 8): these exhibit on the joint- 
surfaces the peculiarity of the fossils being thrown out into strong 
relief by the partial solution of the softer calcareous matrix, pro- 
bably by the action of water charged with carbonic acid. 
3. The zone of Ostrea Sowerhyi in the “ Bottom Jubs.” This 
Ostrea occurs in some sections in great abundance in the under- 
lying clay B. 
As to the fossils contained in these beds, I would particularly 
refer to the cast of a large smooth Ammonite, some 15 inches in 
diameter, formerly in Miss Baker’s collection (now in the British 
Museum, and as yet, I believe, undescribed*, two similar Ammonites 
having been obtained by me from the Great Oolite at Blisworth )—to 
a remarkable fish-jaw, I believe of Lepidotus—to the great number 
of fish-palates, some probably of Strophodus magnus and S. sub- 
reticulatus, and teeth of Saurians—to the abundance of large Pholado- 
mye, Pinna ampla, Natice, Nautilus Baberi, and N. subtruncatus, 
Clypeus Miillert and C. Plotiti—and to the characteristic zone of 
Ehynchonella concinna at the base. 
The section of the pit marked 6 shows a continuation of the beds 
of pits a; and it would be merely repetition to give it in detail. In 
this pit, however, the Rhynchonella zone at the base is usually 
accessible, and is sometimes seen to pass into the underlying blue 
clay B. 
The same fossil forms which are abundant in pits a abound also 
in pit6. Here was found the remarkable Pandanaccous fruit figured 
and described by Mr. Carruthers, F.L.S., F.G.S., of the British 
Museum, in the Geological Magazine, April, 1868, under the name 
of Kaidacarpum ooliticum. 
The chief characteristic of the Buttock’s Booth pit (c), which ex- 
poses a section of the lower beds only of pits a and 6, is an abundance 
of fruit of Carpolithes, fish-palates and saurian teeth, and remains 
of crustaceans of two varieties of Hryma, near to E. elegans, Opp. 
Osseous fragments of Teleosawrus have more than once been found 
here. 
Underlying the iassionen is a bed of blue or dark grey clay, B, of 
a thickness, ascertained by well-sinking, of 14 feet, which is also to 
be classed as Great Oolite. The junction of the limestone with, 
and indeed its passage down into, this clay, is to be seen in the 
bottom of the pit 6. Here the zone of Rhynchonella concinna and 
Modiola imbricata extends into the Clay itself. The junction is also 
* Since the reading of this Memoir, Mr. Htheridge has examined the Am- 
monite in the British Museum and identified it as an old and smooth individual 
of Ammonites gracilis, Buckman. 
VOL, XXVI.—PART I. 20 
