J. W. JTTDD ON THE SECONDAEY ROCKS OP SCOTLAND. 701 



In Ardnamurchan, Mull, and Morvern the Infralias is not exhi- 

 bited in any good connected sections. The strata of this age appear, 

 indeed, to he of insignificant thickness as compared with their equi- 

 valents in Skye, Kaasay, and Applecross, and occasionally seem to 

 be on the verge of total disappearance. At the outlier of Beinn-y- 

 Hattan the Infralias appears to have thinned out altogether. There 

 are some isolated deposits in the north of Mull (as at Ru-na-Gal, 

 Calve Islet, and one or two other points) which, though probably of 

 this age, are in too altered a condition for satisfactory determination. 

 At Torosay, and again between Duart House and Duart Castle, the 

 compact limestones and pebbly grits of the Infralias are fairly well 

 exposed, but do not attain any great thickness. The same is the 

 case with some larger exposures on the south side of the island of 

 Mull. 



b. The Lower Lias. 



The strata of this age are very largely developed in the Hebrides 

 and adjacent mainland of Scotland, and constitute a series of deposits 

 (often richly fossiliferous) with a total thickness, in some places, 

 of at least 400 feet. In the most southern part of the area we are 

 describing, the Lower Lias beds most strikingly resemble, both in 

 their mineral and palseontological characters, their equivalents in 

 England ; and the great floors of limestone and shale crowded with 

 Gryphcea arcuata, Lam., and abounding in Lima gigantea, Sow., and 

 Ammonites of the group of the Arietes, which are so well exposed at 

 Loch Aline and some other points in the Western Highlands, cannot 

 fail to recall to the mind of the most superficial observer the strata 

 of the same age in this country, namely the well-known Lima- or 

 Bucklandi-be&s . 



But when traced further northwards, these strata are found under- 

 going some remarkable changes in their characters and fossil con- 

 tents — changes which tell unmistakably of the prevalence of some- 

 what different conditions as existing in those parts of the Liassic sea. 



lies not with Maeculloch, but with the map on which he recorded his observa- 

 tions. It is clear that the indentation of the coast where the two formations 

 are made to meet is intended for the harbour of Lussay, and not that of Obe 

 Breakish, as the later writer supposes ; and this is shown by the fact that the 

 name of "Lucy " is inserted on the map and mentioned in the text of the work 

 as occurring at the point of junction of the two formations. (Western Isles of 

 Scotland, vol. i. p. 819.) It is greatly to be regretted that a writer in the 

 Journal of this Society, basing his criticisms on this and equally mistaken pre- 

 mises, has permitted himself to make charges of actual fraud against his prede- 

 cessor. Nothing is easier than this criticism of the old work of a geological 

 pioneer by one who is furnished with accurate modern maps, and has the 

 advantage of the discoveries of later thinkers to guide him. But surely before 

 such a painful charge was made it would have been more fitting that the utmost 

 care should have been taken to avoid misrepresentation, that the fullest 

 consideration should have been given to all the facts of the case, and the amplest 

 allowance made for the difficulties under which Maeculloch laboured in the 

 want of even approximately accurate maps, at the early date (1819) at which 

 his researches were carried ou. 



