The Liassic Succession of Pahay, Inner Hebrides. 551 



cliS section, starting about twelve feet above the shore-line, yielded 

 Polymorphites of the caprarius group at the base, at three, six, nine, 

 ten, and eleven feet up, whereas farther north, and also twelve 

 feet above high- water mark, the same caprarius group was 

 encountered at levels of three, five, six, nine, and thirteen feet up, 

 accompanied by Tragoph/lloceras numismalis at three, five, and 

 thirteen feet levels. Similar beds with red nodules on the shore 

 below yielded only belemnites and pelecypods, and may correspond 

 to the barren shales below X^^ and again below X^. The reefs of 

 the south and south-east coasts with their numerous dykes could 

 not be correlated with the above sequence. It may be added that 

 the small exposure of Pabay Shales at Tobermory in Mull yielded 

 only Polymorphites of the capmTius group in abundance, and that 

 some of the species of ammonites recorded by Professor Judd,^ 

 notably A. oxynotus, may be based on misidentifications. The 

 impression of an Echioceras of the raricostatur zone, however, has 

 been found in a pebble, off Tobermory. Conversely, the Raasay 

 beds ^ with Acanthopleuroceras and Uptonia probably belong to the 

 ibex and uppermost jamesoni zones, and Mr. Buckman's ^ 

 " Wessexian " sequence, based partly on the Raasay succession, 

 appears to require considerable modification. 



Dr. Lee ^ estimated the thickness of the Pabay Shales in Raasay 

 to be round about 600 ft., of which some 200 ft. at the top would 

 include the valdani-jamesoni-annatmn zones. In the south of 

 Strath, Mr. Barrow ^ put their thickness at fully 700 ft. The 

 sequence in the ibex and jamesoni zones represented above, allowing 

 for presumed repetition of certain beds by faulting, shows a net 

 thickness of little over a hundred feet. 



^ " The Secondary Rocks of Scotland," third paper ; " The Strata of the 

 West Coast and Islands," Q.J.G.S., vol. xxxiv, 1878, p. 716. 



2 " Mesoz. Rocks of Applecross, Raasay and North-East Skye." Mevi. Geol. 

 Surv. Scotland, 1920, pp. 70 and 81. 



^ " Jurassic Chronology," I. Lias. Q.J.G.S., vol. Ixxiii, 1918, p. 266. 



* L.c. (Applecross Mem.), p. 17. 



5 L.c. (Glenelg Mem.), p. 106. 



