Correspondence — Mr. D. Mackintosh. 429 



NEW AND EXTENSIVE SECTIONS OF BOULDEE-CLAY AT 



LIVEEPOOL. 



SiE, — That your readers, during the tourist season, ma}'- have an 

 opportunity of seeing a series of the largest and most important 

 sections they may ever meet with in their lives, I lose no time in 

 directing their attention to the excavations for the new Canada 

 Docks, near Bootle Station, Liverpool. There is a lower glacial 

 clay (which is worked with the pick) underlying a greater or less 

 thickness of non-g]acial gravel and sand; but the great deposit 

 exposed is the upper or brick clay (which is worked with the spade). 

 Though I had previously seen boulders in this clay in different 

 localities, I was not prepared to find such an array of large blocks 

 more or less imbedded in the clay at different levels, and apparently 

 in the spots where they had been dropped. The majority, so far as 

 my observations extended, were greenstone, and numbers of them 

 might be seen lying near to each other as if they had been picked 

 up from the sam_e spot (in the Lake District) by a mass of coast-ice, 

 which floated them and laid them down without severing their family 

 connexion. Many of the boulders were quite five feet in length, 

 and in shape varied from round to sub-angular and angular. Most 

 of them were intensely glaciated. J have to thank Mr. Morton, F.G.S., 

 for directing my attention to the above sections. 



D. Mackintosh. 



LLANDOVEET EOCKS IN THE LAKE DISTEICT. 



Sir, — In reply to Mr. Aveline's last letter, I beg to state that the 

 evidence relied on by me in drawing up the Table was obtained 

 from the published statements of the authors whose names appear 

 at the head of the column referred to (p. 156) ; and who, I believe, 

 have not only obtained " fossil evidence " sufficient to warrant their 

 speaking " confidently of their position," but have been able also to 

 qualify this by " a careful stratigraphical survey of the rocks." 



I am permitted also to state that Professors Harkness and Nichol- 

 son have recently discovered a group of fossils in these mudstones 

 which, if fossil evidence is to be recognized as of any importance 

 (and he must be a bold man who in the present state of our know- 

 ledge is prepared to cast this evidence entirely aside), make it 

 almost impossible for these beds to be so high in the succession as 

 Mr. Aveline would have us believe. Moreover, these fossils are 

 specifically for the most part identical with those of the same genera 

 found in Wales in Upper Bala and Llandovery rocks. The full 

 particulars of this interesting and important discovery will be com- 

 municated by Professors Harkness and Nicholson to the British 

 Association at Glasgow ; but I am allowed to state here that the 

 result has been to prove " that the sequence from the Coniston 

 Limestones to the mudstones is perfect, and that there is no uncon- 

 formability, but that the mudstones must be regarded as the highest 

 portion of the Bala series," or as the equivalents of the Lower 

 Llandovery. 



