4^ Dr. Mac Culloch's Sketch of the 



but the same interference is not visible there, although the paralle- 

 lism is perfect. 



From either end of this junction the limestone beds of the 

 upper series may be traced all round the point which separates 

 Loch Eishort from Loch Slapin, intersected every where like the 

 former by trap veins. Neither the thickness, the number, nor 

 the order of these beds can be ascertained, as they are much too 

 complicated and difficult of access to admit of such an examination. 

 The very attempt would be a superfluous endeavour after accuracy, 

 since enough of them is ascertained to prove that only which is 

 important to be known, the order of their connections with the 

 neighbouring rocks, and the characters by which they can be iden- 

 tified with more distant strata. In general they are formed of thin 

 and thick laminas, composed of a dark blue earthy limestone, at 

 times somewhat more crystalline, and variously interleaved with 

 argillaceous schist of various dimensions. These beds, like the 

 former, are inclined at an angle of about 25° ; they seem most re- 

 gular as well as thickest at the point of separation between the two 

 Lochs Eynort and Slapin, while near the very same place they are 

 also found in very thin schistose laminse, so that I imagine there is 

 no rule to be laid down respecting them; they are found occu- 

 pying the island of Heast, as well as a long ridge of rocks which 

 here intersect Loch Eishort ; and they may also be traced at Ord, 

 and further down this shore even as far as Gillan, following the 

 red sandstone, for the same geographical reasons, probably, that I 

 assigned when speaking of that substance. Here however the 

 intermediate bed, that which contains the marble, is deficient, and 

 we have already seen that the blue quartz and schist are also de- 

 ficient, so that the order is here mica slate, red sandstone, schistose 

 limestone ; instead of mica slate, blue schist with quartz, red 



