322 PROCEEDINGS OP THE GEOLOGICAL SOCIETY. [Feb. 26, 



relations are not revealed to ns till we find them at Camus-Inivaig, 

 superimposed as Inferior Oolite on the top of the Upper Lias. This 

 is sufficient evidence to justify the view of the upthrow and erosion 

 above suggested*. 



The first of our Sections is taken close to Tanna Point on the 

 south-east ■ side of Portree harbour, where, as already noticed, the 

 series rises to a great height under tbe basaltic precipices of Inivaig 

 mountain, which reaches the height of 1346 feet. There are many 

 faults and slips upon these impassable slopes; and hence it was 

 necessary to stand out a little in a boat, and select a spot free from 

 both causes of error, and where it was possible to climb to a con- 

 siderable height, in order to make sure of the true sequence. 



After this reconnaissance the boat was pushed into a long and 

 narrow cleft, made by the wearing away of a large whin-dyke, 

 whose course could be traced far up into the overlying trap ; and 

 the following clear section was obtained, including the Middle and 

 Upper Lias and base of the Inferior Oolite. 



Section I. (order descending). 

 Upper Lias, with the characteristic Ammonites communis throughout. 



ft. in. 



1. Argillaceous dark blue limestone 4 



2. Black shales 3 



3. Line of nodular blue limestone, showing oolitic structure 



in part and with pyrites ; Ammonites communis and 



A. falcifcr abundant and of large size 3 



4. Stiff black shales, slightly micaceous, with Ammonites fal- 



cifer, A. heterophyllus, Inoceramus dubius, &c 8 



5. Brown crystalline limestone 6 



G. Black friable shale , 1 6 



7. Compact blue argillaceous limestone , 1 3 



8. Finely laminated black shale, with Ammonites bifrons ... 9 



Total thickness 15 7 



Other fossils furnished by this series will be found in the lists appended, 

 Underneath these beds come about 60 feet (estimated) of the Middle Lias, 

 as follows, in descending order. 



Middle Lias. 



«, Yellow calciferous sandstone, the upper part more calcareous, and approxi- 

 mating to the dark blue limestone, at the base of the Upper Lias ; Ammo- 

 nites-spincttns beds. 



b. Bluish micaceous sandstone, thinly bedded with lines of large blue calcareous 



nodules and septaria, with Ammonites margaritatus, Pecten csqv.ivalvis, 

 P. liasinus, Limea acuticostcc, Pcntacrimis amalthei, &c. (See lists.) 



c. Hard micaceous sandy and calcareous shales, with rows of spherical calcareous 



nodules. Pecten <squivalvis very large, Pholadomya ambigua, Plicatula spi- 

 nosa, &c. This bed descends to the sea-line along the whole shore, from 

 Portree harbour to Caraus-Inivaig ; and there are no means of estimating 

 the total thickness. 



* Not having made myself up on the literature of the subject before my first 

 visit to -Skye, as it is not always ready to one's hand, I had satisfied myself that 

 the beds on the east side of Sligachan were Lower Lias, and that the sand-rock 

 on the west side was a continuation of that of Camus-Inivaig, before I found 



