1873.] JUDD THE SECOOTARY ROCKS OF SCOTLAND. 181 



of sand formed by the grinding-up of the softer portions. In the 

 reefs on the shore these crushed sandstones are sometimes found 

 again completely indurated ; and the masses then sometimes resemble 

 walls of the rudest Cyclopean architecture. This apparently brec- 

 ciated condition of the rock must not, however, be confounded with 

 a phenomenon displayed in the same series of strata in their northern 

 development, which is of a totally different character and origin, 

 and will hereafter be particularly described. 



This series of beds in many parts yields a considerable number of 

 fossils. The limestones, which are sometimes wholly made up of 

 specimens of Exogyra nana, Sow., and Ostrea (Exogyra) Bruntrutana, 

 Thurm., in places contain also a considerable number of other species. 

 Unfortunately, however, the majority of the shells are very frag- 

 mentary, or when entire are incapable of removal, owing to the 

 hardness of the matrix and the decomposed condition of the shells. 

 Small Gasteropods and spines of Echinoderms are very abundant ; 

 but entire specimens of this latter class seldom or never occur. Very 

 conspicuous, too, in these beds are the gigantic fihynchonellce (li. 

 Sutherlandi, Dav.). Great masses of drifted and waterworn coral, 

 Isastrcea oblonga, Edw. & Haime, also occur in them. The finely 

 laminated clays contain in many places numerous crushed specimens 

 of Ammonites, Ostrea, Lima, Avicula, Pecten, &c, and of the remark- 

 able long slender Belemnites (B. obeliscus, Phil., and B. spicularis, 

 Phil.), which are so characteristic of these beds *. The associated 

 grits contain the same fossils, but in a much worse state of preserva- 

 tion, and nearly always as easts. The limestones of this series were 

 formerly burnt in kilns on the shore at Port Gower, Helmsdale, and 

 Navidale ; but this use of them is now abandoned. 



Very remarkable and interesting in connexion with these Upper 

 Oolite strata is the large and beautiful flora which they yield. On 

 splitting open some of the fissile grits and sandstones, leaves of Cyca- 

 dean plants and fronds of ferns are found spread out as in an herba- 

 rium. Stems of Cycads, and large masses of wood, with cones and 

 buds of Coniferse, also occur. This interesting flora was first brought 

 under the notice of geologists by Hugh Miller, by whom some of the 

 more remarkable objects were figured in the last two chapters of his 

 ' Testimony of the Rocks.' Among the beds of limestone, sand- 

 stone, grit, and laminated shale are sometimes found much carbona- 

 ceous matter, occasionally, as at Gartymore, forming thin and impure 

 seams of lignite. 



The thickness of this great series of beds can nowhere be exactly 

 determined. A continuous section near the Allt-gharashtiemore ex- 

 hibits a succession of over 500 feet ; and the whole series is probably 

 not less than twice that thickness. 



The following is the list of fossils found in these strata : — 



* I bave already (page 110) noticed how erroneous information concerning 

 the localities from which certain specimens were derived led to the Belemnites 

 being referred to the Middle instead of the Upper Oolite in Prof. Phillips's 

 Memoir. 



