1873.] P.EYCE — JURASSIC ROCKS OE SKYE AND KAASAT. 339 



the nature of the- cooling surfaces, by which the heat of fusion 

 parted from them. Yet we often find true basalts, syenites, and 

 greenstones upon the existing surface, as well as amygdaloids, while 

 the latter are often at the base of deep sections ; and such differ- 

 ences are therefore not of much value. The basaltic sheet forming 

 the top of the Staffin cliffs, is certainly not interposed. It is con- 

 tinuous and superficial inland to the base of the Storr range, of 

 which it is but one of the basement-sheets, superior to all the Oolitic 

 strata, and a member of the overlying series. 



Finally, then, when we consider that the sheets of trap inter- 

 calated in all our sections alter the sedimentary strata both above 

 and below, and that the bed interposed in the Camus-Inivaig sec- 

 tion emerges at the top of the section and becomes continuous with 

 the overlying trap, the conclusion is forced upon us that the various 

 intercalated sheets belong to the period of the outflow of the over- 

 lying trap series. 



EXPLANATION OE PLATE XI. 



Pig. 1. Geological sketch map of the islands of Skye and Eaasay. 



2. Cliff-section of the coast of the Isle of Skye, from Loch Sligachan north- 



wards. 



3. Cross section through the Isle of Eaasay. 



4. Cross section in the line of fig. 3, continued through Skye. 



5. Section across Loch Sligachan. 



6. Section east of Loch Me- Alt, showing the denudation of the trap. 



7. Coast-section, showing the rise of the Jurassic beds. 



Appendix. — On tli6 Paleontology of Skye and Eaasay. By Ralph 

 Tate, Esq., Assoc. Linn. Soc, F.G.S. 



I. PAL2E0NT0L0GICAL HORIZONS, SkYE, &C, AND LlSTS OE FOSSILS. 

 EH2ETIC ? 



The conglomerates, quartzitic sandstones, and brick-red and grey- 

 ish sandstones, forming the cliff Bu-na-Leac, may be of this age. 

 No fossils observed. 



Lower Lias. 



Hettangian Series(=zones of Ammonites planorbis and A. an- 

 gulatus). — The blue argillaceous limestones and indurated shales 

 constituting the under cliff on the north side of Bu-na-Leac Bay, 

 I regard as the basal portion of the Lower Lias. The following 

 fossils were obtained : — 



Natica, sp. Pecten poll us, If Orb. 



Ostrea irregularis, Mimst. Astarte Gueuxii, B'Orb. 



Plicatula Deslongchampsi, Terq. Lima punctata, Sow. 



Perna infraliasica, Querist. Mytilus Hillanus, Sow. 



Beds 1 to 4, Geikic's section, may probably belong here. The 

 fossil evidence, however, is inconclusive, the coral being peculiar, 

 and the other two species recorded from these beds occurring else- 

 where in the zones of A. awjidatas and A, Bacldandi, and even 



