in Sutherland, Ross and the Hebrides. 363 



ceous shale of the adjoining island of Pabba. This shale appears therefore, 

 from its position, to belong to the upper part of the lias ; — a conclusion which 

 is strikingly confirmed by a most abundant suite of well preserved fossils, of 

 which the greater number of the species have been identified as characteristic 

 of that formation. 



By way of concluding my remarks on the oolitic series of the Western 

 Islands, it may be necessary to refer to the Section (PI. XXXV.) which exhibits 

 the succession of those deposits on the eastern coasts of Skye, from the highest 

 beds in Trotternish in a descending order through the contiguous isles of 

 Rasay, Scalpa, and Pabba, to the lowest Has limestone of Broadford and Lucy. 

 In this section the overlying and intrusive trap rocks are entirely omitted, and 

 the regular strata are alone represented. It is from this observed order, com- 

 bined with the characteristic fossil shells in the several beds, that satisfactory 

 evidence has been obtained for the establishment of the groups described in 

 this and the preceding Memoir. At Applecross, only one small trap dyke has 

 been noticed ; and the strata being there undisturbed, the lias is superimposed 

 on the red sandstone of the west coast, in an order similar to that which has 

 been described on the east coast near Cromarty. Prom these instances of 

 junction, in situations so far distant from each other, it may be inferred that 

 the lias and oolitic series of the North of Scotland succeeded generally to 

 the red sandstone and conglomerate, occupying perhaps large tracts, of which 

 isolated patches are all that now remain ; owing to the elevation of granite, 

 the intrusion of trap, and various other operations which may have subse- 

 quently affected the earth's surface. 



Since the publication of the former part of this memoir, two small patches 

 of blue clay, one of which is about forty feet thick, containing organic remains, 

 have been discovered overlying the red sandstone and conglomerate, in a ravine 

 atGamrie*, near Troup Head, Banffshire. Through the urbanity of Dr. Knight 

 and Mr. A. Murray of Aberdeen, the Geological Society was furnished with 

 a portion of these fossils ; they consisted entirely of fish, too imperfect to be 



* I examined this coast in detail, Sept. 1826 ; but at that period the existence of these fossils 

 at Gamrie was unknown, and they were only discovered in the subsequent winter by a great fall 

 of blue shale, occasioned by the overflow of a mill. course. Professor Sedgwick and myself 

 having in our recent excursion passed by another route to the south, we had no opportunity of 

 examining the locality ; and I have therefore availed myself of the information communicated by 

 the gentlemen named in the text. 



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