324 PEOCEEMKGS OF THE GEOLOGICAL SOCIETY. [Feb. 26, 



Harbour the limestones are 40 feet thick. The whole series has 

 about the same dip and inclination as in last section. Ammonites 

 Murchisonce is abundant in the sandy shales near the top of the series, 

 but it occurs also throughout. Division C is characterized by Avicula 

 eostata, Rhynclionella concinna, Terebratula lagmalis, and Ostrea Soiv- 

 erbii. 



Section III. 



Another section of considerable interest in this part of the series 

 can be easily visited from Portree, and is approached by land without 

 difficulty. It is to be seen five miles south of Portree on the east 

 side of Camus-Inivaig bay, where the fossiliferous beds emerge from 

 under the sea-line. The section is as under, in ascending order from 

 the sea-level. 



Lias and Oolite. 



1. Middle Lias; a yellow calciferous sandstone, with sandy shales in the 



upper part of the series ; descends under the sea-line. 



2. Upper Lias shales about 10 feet; without limestone. 



3. Sandstone of the Lower Oolite without strong lines of stratification ; in the 



lower part grey flaggy sandstones, on the top yellow sandstones with irre- 

 gular oblique bedding. 



4. A sheet of basaltic rock, chiefly compact dolerite, about 60 feet thick. It 



strikes the sea-line a little to the west of the section, forming the tide-way, 

 and gradually ascends eastwards ; finally it thins much in this direction, 

 and cutting through the beds No. 5 above, runs on to join the overlying trap. 



5. Flaggy sandstone of the Oolite ; upper part of Lower Oolite, with oblique ir- 



regular bedding, about 40 feet. 

 G. Rocks of the basaltic plateau, declining towards the head of Camus-Inivaig, 

 extending thence to Portree and Sligachan, and westward over the 

 interior moorlands. The dips here are a little to S. of W., at angles 

 of8°tol2°. 



The lines of contact of bed ~No. 4 show remarkable changes in the 

 sedimentary rock. Where the Oolitic sandstone No. 5 is argillace- 

 ous, it is converted by contact with the underlying trap into a dark- 

 blue, almost black Lydian stone, banded with parallel grey streaks : 

 when siliceous, the rock is changed into a hard dark-grey sandstone, 

 almost a quartzite. Beds of coal, interstratified with layers of 

 sand, the joint thickness being about 12 or 15 inches, occur at in- 

 tervals along the whole line of contact. The coal is of an earthy 

 grey and crumbling on the oitter surface ; but within it approaches 

 to jet in hardness and lustre. The changes indicate the injection of 

 the trappean rock after the deposition of the Oolitic beds, and most 

 probably contemporaneously with the outflow of lava which formed 

 the overlying basaltic sheets. 



Faults in this division. — Several faults occur in the division of the 

 fossiliferous beds marked off by the two great depressions at Camus- 

 Inivaig and Portree. One of these is a little to the west of Tanna 

 Point, and brings down the upper sand-rock to the base of the lower 

 bed of the Oolite, a downthrow of about 50 feet. A second occurs 

 half a mile southwards, and brings the Inferior Oolite to the sea- 

 level, and the sand-rock to the height of about 60 feet above it. 

 There are also many slips. The secondary rocks have subsided en 

 masse, without disturbance of the order of the beds, and brought 



