372 J. F. BLAKE AND W. H. HUDLESTON ON 



tortuous valley aud the Chalk escarpment, we should not omit to 

 describe briefly the remarkable section at Hildenley, which is about 

 halfway between Malton and Castle Howard. 



In the quarry on Hildenley Heights there is a peculiar limestone 

 with a marked Rag or Upper Corallian fauna, the only trace of coral 

 now remaining being some remarkable cavities in the lower side of 

 some of the beds, which represent places where branches of corals 

 have been, and where they undoubtedly have grown. The stone is 

 extremely fine in the grain, is said to contain about 95 per cent, of 

 lime carbonate, and has the appearance of having been deposited as 

 fine mud within a tranquil lagoon or bay. It rests upon oolite, and 

 is supposed by Sir Charles Strickland to be flanked also by that class 

 of rock. The stone, from its homogeneous character, is valuable for 

 building, and especially for carving, with the exception of those 

 beds which contain a small Ostrea. The valves of these are partly 

 silicified, and the chisels of the workmen thereby spoilt. It is evi- 

 dent that there is a considerable amount of chalcedonic silica in 

 these beds ; and the action which this silica has undergone is not 

 without its effects upon the fossils : indeed the variety of fossiliza- 

 tion is remarkable. The fauna indicates a high position in the 

 series ; and some of the most characteristic fossils are those of the 

 Upper Calcareous Grit of other places, as Modiola cancellata, Rom., 

 and Lucina aspera, Buvig. 



The following partial list will serve to show the character : — 



Ammonites varicostatus, Buckl. 

 Natica grandis, Milnst. 



clio, Z>' Orb. 



Lucina aspera, Buvig. 

 Protocardiurn isocardioides, Bl. 8f H. 

 Area pectinata, Phil. 

 Modiola cancellata, Bom. 



Gryphcea, large sp. 

 Exogyra nana, Sow. 

 Pygurus pentagonalis, Phil. 

 Collyrites bicordatus, LesJce (large;. 

 Pseudodiadema hemispksericum, Ag. 

 Hemicidaris intermedia, Flem. 

 Cidaris florigemma, Phil. 



The upper part of the quarry is just on the edge of the little 

 plateau called Hildenley Heights. The beds dip to the S.E. about 

 4° or 5°, i. e. obliquely to the steepest side of the hill, which is 

 about S. | W. In this way they fall to the 275-feet contour, 

 behind the hall ; and the next beds proved on the dip, at the base of 

 the hill, are the argillo-calcareous beds, which undoubtedly repre- 

 sent the supracoralline series, but in a form having the greatest affi- 

 nities with the " throstler " (see Pickering Section, p. 335). They 

 are still more closely related, as we shall see subsequently, to the 

 " cement-stone " of N. Grimston. These beds were proved in the 

 garden; and the foundations of the hothouses are laid in them. 

 A short distance due south of this, on the 200-feet contour, is the 

 brickyard, which gives the best and most characteristic display of 

 the base-beds of the Kimmeridge Clay of any inland section in York- 

 shire with which we are acquainted. It furnished the following : — 



v.c. Ammonites mutabilis, Sow. 



Alaria mosensis, Buvig. 

 v.c. Ostrea deltoidea, Sow. 

 v.c. Exogyra nana, Sow. 

 c. Avicula aidilignensis, Blake. 



Trigonia (clavellate sp.). 

 Thracia depressa, Sow. 

 Myacites oblatus, Sow. 

 Pholadomya, sp. 



