THE JURASSIC FLORA OF SUTHERLAND. 645 



"Exposed for the most part in rugged reefs along the foreshore, the Jurassic rocks 

 appear in places also at the base of the low cliffs formed of the recent and Pleistocene 

 deposits and for a short distance along the banks of the burns. It is, however, difficult 

 to ascertain in detail the sequence of the strata, and no reliable estimate of their thick- 

 ness can be given. The reefs on the whole have a general dip seawards, the strike 

 coinciding roughly with that of the coast-line. The strata are much faulted, bent, and 

 twisted ; they are traversed by pseudo (sandstone) dykes and are weathered into 

 fantastic shapes. They include shales, limestones, sandstones, conglomerates, and 



Photograph of the coast of Sutherland, looking south ; in the foreground is a block of Kimeridgian rock, 

 in the middle distance the platform of Kimeridgian strata and superficial deposits, with the granite 

 hills to the right. 



boulder-beds. The general sequence is as follows, the higher divisions being exposed in 

 the northern part of the area from near the Ord of Caithness to near Portgower : — 



6. Shales, conglomerates, and boulder-beds, with blocks of flags (Old Red Sand- 

 stone), lignite, large portions of tree trunks, and other plant remains, 

 Bennettites Peachianus Carr. and Zamites Milleri Zig. [ = Zamites 

 Buchianus (Ett.)], also Corals {Isastrsea), spines of Cidaris, Ostrea, 

 Exogyra, and Ammonites near to A. giganteus Sow. 



5. Calcareous sandstones and shelly limestones, with Rhynchonella Suiherlandi 

 Uav., Exogyra, Ammonites endoxus D'Orb., A. alternans von Buch. 



4. Shaly beds with plant remains. [The plants include Nilssonia, Hausmannia, 

 Sagenopteris, Elatides, etc.] 



3. Shales with thin bands of calcareous sandstone, more or less conglomeratic, 

 spines of Cidaris, Ammonites cf. A. mutabilis Sow., A. alternans von 

 Buch, Belemnites, Pecten articulatus Schloth. 



2. Alternation of sandstone and shale. 



