THE TRAP ISLANDS. 73 



intermediate point therefore, Mull becomes connected with 

 Egg, and ultimately, with Sky and the remaining islands ; 

 and thus the geographical continuity of the whole deposit 

 is in a manner restored. The geological identity of the 

 strata throughout the whole, may be deduced with as little 

 hesitation, from the various points of resemblance between 

 the several beds in the different islands, and, among others, 

 from the correspondence of the organic remains. To the 

 latter proofs, as they may be collected from the various 

 descriptions already given, I may now add, that some 

 of the beds of the Morven limestone contain pectines, and 

 are undistinguishable from those of Scalpa. The identity 

 of those two remote portions of the series is thus esta- 

 blished, and the common nature of the whole proved as 

 far as it is possible in these dislocated regions, to prove 

 any thing respecting the original continuity of the now 

 separated portions. The geologist who has had the good 

 fortune to investigate these rocks in the extensive plains 

 of England where he can trace them for many miles, must 

 excuse him who, in Scotland, is condemned to pursue them 

 with incessant watchfulness, and by the most minute indi- 

 cations, through an intricate and difficult country, if he 

 cannot produce, in confirmation of his views, a mountain, 

 where Nature has only preserved specimens of her former 

 strata. 



Considering the identity of the secondary strata through- 

 out these islands as being fully established, it remains next 

 to inquire whether they present marks of any connexion 

 more extensive, or whether they do not rather form a 

 separate deposit ; being analogous to others of the same 

 nature, but, in a local view, independent. 



It has appeared in the preceding remarks, that both 

 their superior and inferior portions rest on the primary 

 rocks in different places. Inch Kenneth presents the only 

 example of that which has been esteemed the natural 

 termination of this series downwards ; and it may therefore 

 be concluded that Mull occupies a position near the border 



