1873.] BRYCE JURASSIC ROCKS OP SKYE AND RAASAT. 323 



The usual character of the top bed of the Middle Lias is that of a 

 hard thick-bedded calcareous sandstone of a yellow or yellowish brown 

 colour, hard and tough, with occasional beds of crystalline limestone, 

 resembling a marble of the Carboniferous formation. The external 

 surface is often honeycombed, the holes being so large that a man's 

 fist can be thrust into them ; there are also rows of large lenticular 

 reddish masses consisting of a fine-grained limestone, extremely hard 

 and tough, and often showing a concentric structure. The beds are 

 also ridged with harder portions, whose cement is iron or lime, and 

 which project, as being more enduring. Bor the other fossils see 

 the lists annexed. 



The Oolite Sandstones are seen in this section to rest upon the 

 Upper Lias ; but the bed in contact can be reached only in this place. 

 The following section is taken further west, and is accessible from 

 the foregoing only by water. A cleft in the steep hill-slope ascends 

 from the west side of a huge fallen and overhanging mass of Middle 

 Lias to the basaltic plateau at the top of the cliffs. The Middle and 

 Upper Lias form the lower part of the section, with the same litholo- 

 gical characters as those just described, and yielding similar fossils. 

 Besting directly on the Upper Lias, the Inferior Oolite here forms 

 three very distinct beds. The beds all dip nearly west at small 

 angles, 7° to 12°. 



Section II. 



The lower portion, which may be called subdivision A, is about 

 100 feet thick, consists of dark grey sandstones, alternating with 

 micaceous, argillaceous, and sandy beds, and, near the top, shaly 

 sands extensively stained with carbon, and containing pieces of jet ; 

 a blue calciferous sandstone terminates the series above. The bottom 

 bed has the characteristic fossils, Ammonites MurcJiisonce, Pecten 

 Deivalquei, and Lucina Wrightii. Belemnites of several species occur 

 throughout, more especially in the sandy beds. The fossils are most 

 abundant in the lowest beds (see lists). 



Subdivision B. (Upper Series). — This is a yellow or white sand- 

 rock, very easily broken under the hammer, and then into powder 

 under the hand ; it is about 50 feet thick, and contains many plant- 

 remains too imperfect to be determined, and also occasionally small 

 pieces of jet. The beds of contact with A are of a grey colour. 



Subdivision C. — This is on the top ; is from 1 to 3 feet thick, and 

 consists mainly of a shaly crystalline limestone, with sandy shale 

 partings ; Avicida costata and Bhynchonella concinna occur. 



These beds are those which Sir B. Murchison conjectured to be the 

 representatives of the Cornbrash and Forest Marble ; the beds, indeed, 

 fall naturally into two lithological divisions, which are closely ana- 

 logous to those of the Yorkshire coast, near the base of the Oolitic 

 series : our third division C is here insignificant ; but inside Portree 



that SirR. Murchison had made the observations already quoted, or that Dr. 

 Macculloch had traced the sand-rock into continuity with the beds at Camus- 

 Inivaig. Dr. Macculloch is often vague and unsatisfactory, but very seldom in- 

 deed does he commit himself to a statement which we haye found incorrect. 



