H. -S. Woodward — On the Midford Sands. 513 



While therefore the actual physical and zoological distinction can 

 be traced in a westerly direction for more than twelve hundred 

 miles, and in a north-easterly direction for six or eight hundred miles, 

 and for an equal distance in a southerly and south-westerly direction, 

 I can scarcely suppose that the few facts observed within limited 

 areas, and not yet submitted to the test of comparison, will change 

 the views of geologists upon the distinctive character of these 

 formations. 



In bring-ing this brief resume before the Geological Section of the 

 British Association, I have indulged in the hope that the facts might 

 be of some use in a comparison with British Middle and Upper 

 Silurian formations, which can be so clearly recognized in Canada 

 and the United States. 



V. — 'Note on the Midpokd Sands. 



By H. B. Woodward, F.G.S., 

 Of the Geological Sm-yey of England and Wales. 



THE term " Midford Sands " suggested by Professor Phillips ^ for 

 the Sands which occur between the Inferior Oolite and the 

 Upper Lias Clay, gives us a very happy name, and one that has been 

 long wanted for these beds ; for hitherto although they have been 

 called by many names, not one has been generally adopted. They were 

 first discovered and studied, so Professor Phillips tells us, by William 

 Smith, in the picturesque cliff which overhung his house at Tucking 

 Mill, near Midford— a little hamlet about three miles south of Bath, 

 and situated in one of those delightful valleys formed by the river 

 Avon and its tributaries. The deposit was called by him " Sand 

 of the Inferior Oolite," and so it was known until Dr. Wright 

 in 1856 "^ called the classification into question on palasontological 

 grounds, and maintained that the fossil evidence indicated that the 

 Sands belonged rather to the Lias than to the Inferior Oolite. He 

 gave them the name of "Upper Lias Sands," by which they have 

 since been usually designated. The classification of Dr. Wright has, 

 however, been objected to, and it may therefore be interesting briefly 

 to review some of the opinions in regard to this question, stating 

 also that most recently given by Professor Phillips. 



Dr. Wright pointed out that wherever the Sands are well exposed 

 (and he gave sections in Grloucestershire and Dorsetshire), they are 

 overlain by a brown iron-shot marly limestone containing "an 

 immense quantity of individuals of several species of Ammonites, 

 Nautili and Belemnites, with a few shells of other MoUusca," and 

 he maintained that this "Cephalopoda Bed" in its organic remains 

 belonged rather to the Lias than to the Oolite formation. The Sands 

 below he found to pass insensibly into the, clays of the Upper Lias. 



Mr. Moore,^ however, has disputed these conclusions. He remarks 



1 Geology of Oxford and the Valley of the Thames, p. 109. 



2 Quart. Journ. Geol. Soc., vol. xii., p. 292. 



3 On the Middle and Upper Lias of the South-west of England. Proc. Somerset 

 Arch, and Nat. Hist. Soc, vol. xiii., 1865-6. 



VOL. IX. — NO. CI. 33 



