108 THE CRUISE OF THE BETSEY ; OR, 



and main rising bold on the east, and its long mountain vista 

 opening to the south. The first fossiliferous deposit which 

 gave me occasion this morning to use my hammer occurs near 

 the opening of the loch, beside an old Celtic burying-ground, 

 in the form of a thick bed of hard sandstone, charged with 

 Belemnites, a bed that must at one time have existed as a 

 widely-spread accumulation of sand, the bottom, mayhap, 

 of some extensive bay of the Oolite, resembling the Loch Port- 

 ree of the present day, in which eddy tides deposited the 

 sand swept along by the tidal currents of some neighbouring 

 sound, and which swarmed as thickly with Cephalopoda as 

 the loch swarmed this day with minute purple-tinged Me- 

 dusae. I found detached on the shore, immediately below this 

 bed, a piece of calcareous fissile sandstone, abounding in small 

 sulcated Terebratulse, identical, apparently, with the Terebra- 

 tula of a specimen in my collection from the inferior Oolite 

 of Yorkshire. A colony of this delicate Brachiopod must 

 have once lain moored near this spot, like a fleet of long-prow- 

 ed galleys at anchor, each one with its cable of many strands 

 extended earthwards from the single dead-eye in its umbone. 

 For a full mile after rounding the northern boundary of the 

 loch, we find the immense escarpment composed from top to 

 bottom exclusively of trap ; but then the Oolite again begins 

 to appear, and about two miles further on the section be- 

 comes truly magnificent, one of the finest sections of this 

 formation exhibited anywhere in Britain, perhaps in the 

 world. In a ravine furrowed in the face of the declivity by 

 the headlong descent of a small stream, we may trace all the 

 beds of the system in succession, from the Cornbrash, an up- 

 per deposit of the Lower Oolite, down to the Lias, the for- 

 mation on which the Oolite rests. The only modifying cir- 

 cumstance to the geologist is, that though the sandstone beds 

 run continuously along the cliff for miles together, distinct as 

 the white bands in a piece of onyx, the intervening beds of 



