have here then before us the passage beds of two formations, the 
Liassic and Oolitic ; but where are we to trace the exact point 
where the one ceases and the other begins? We know that the 
Lias is represented here by the Cephalopoda bed on which the 
Sands rest. But what are the Sands, are they Liassic or Oolitic ? 
i.e., does the fauna contained in them represent an Oolitic or 
Liassic character. Now it so happens that these Sands in our 
own immediate neighbourhood are singularly destitute of organic 
remains calculated to throw light on this point; in fact, 1 know 
not if any organism has ever actually been found in the Sands 
themselves, but in the hard bands of calcareous stone which come 
in here and there we have been more fortunate. And during one 
of my visits to this section I found various organisms, and the 
portion of a shell which in my opinion and in that of Mr. Moore 
belongs to the species which is characteristic of the Inferior Oolite 
i.¢., Rhynconella spinosa. 
Since then I have found portions of Ammonites which have an 
Inferior Oolite character about them.* 
If then these turn out to be true suppositions, we may I think 
come t0 the conclusion that the Sands as represented in our 
vicinity are Oolitic, whatever others may have to say respecting 
those in the neighbourhood of Cheltenham. It is but just here to 
say that there is a third view lately put forth by Professor 
Phillips, which, from his well-known wisdom and judicial caution, 
may perhaps after all be the safest to adopt, i.e. that the Sands 
feebly tie together these great Liassic and Oolitic deposits and 
may be called “‘ Midford Sands,” because, as he says in a foot note 
to his admirable work on the geology of the Thames Valley 
(p. 109), ‘They were first discovered and studied by Smith in 
* Mr. Etheridge has since kindly named these for me as Am. striatulus, 
Am, aalensis, and Am..crassus, and states that they are typical of the 
Upper Lias. Mr. Charles Moore, however, considers them to be common 
to the Lias and Inferior Oolite, 
