SKY. GEOLOGY. SECONDARY STRATA. 321 



to fix our opinions on this point. I shall therefore dis- 

 tinguish it by the name of the gryphite limestone, to 

 prevent it from being confounded, till better proof of 

 its identity be obtained, with the beds of lias above 

 mentioned. 



These calcareous strata are frequently found to contain 

 interposed beds of trap, and principally on the north-eastern 

 shore; which, being often laid bare by the destruction 

 of the softer incumbent materials, are found divided 

 into columnar figures. They are also traversed in various 

 directions by veins of the same rock, which in Sky 

 seem particularly to abound among the softer strata. 

 Whether the apparent beds are also to be considered 

 as veins, is a question that must be discussed when 

 this rock shall hereafter be considered. 



Proceeding along the Broadford shore to a small 

 point north of that village, the junction of the syenite 

 and the limestone is seen ; but the shale is in this 

 place the predominant substance. The overlying dis- 

 position and the contact of the syenite with the inferior 

 beds are here distinctly visible for a considerable space, 

 and are not attended with any disturbance of their 

 regularity or alteration of their texture. But having 

 once arrived here, the boundary of the limestone becomes 

 irregular, nor can it any longer be found in the interior, 

 which now rises into the high group of syenitic hills 

 of which Ben na Caillich is the principal. Although 

 detached portions of the flat beds can still be traced 

 along the shore, they are much intersected and obscured 

 by syenite and trap, nor does limestone again appear 

 for a long space, all the beds visible consisting of 

 shale. At the entrance of the sound of Scalpa these 

 cease and are replaced by a gravelly shore ; after which 

 a patch of limestone again appears, involved in syenite 

 and trap, and no longer disposed in flat beds, but 

 assuming that irregular structure of which numerous 



VOL. I. Y 



