300 Waddington : Yorkshire Naturalists at Wykeham. 



and other fossils. To a collector of geological specimens the 

 Coral Rag is a veritable paradise — there is such a variety of 

 fossils, their condition is exceptionally perfect, and they are not 

 difficult to obtain. Echinoderms, bivalves, univalves, and corals 

 abound everywhere. The curious ' hummocky ' nature of the 

 masses of coral was very noteworthy. It required no great 

 stretch of the imagination, even on the part of a novice, to 

 picture the condition of things that must have existed in the 

 neighbourhood in Jurassic times. The 'Coral Rag' — the last 

 of the British Coral Reefs, with its large rounded masses of 

 coral, grown one upon the other to a great depth ; some of 

 them bored through and through with mollusca, the casts of 

 the borings and the contained shells being still intact, and the 

 insterstices between the coral filled with various marine mollusca 

 — resembles in almost every detail the coral reefs so characteristic 

 of the tropical seas of to-day. Favourite sections in the lime- 

 stone were also seen at Irton Lane and Ayton. These quarries, 

 which were visited and studied by the pioneers of Yorkshire 

 geology, may justly be looked upon as classic ground. Phasia- 

 nella striata, Pseudodiademma versipora, Ostrea nana, Cidaris 

 smiihii, Lima, etc., are amongst the commonest fossils to be 

 collected. In the Irton Lane section a hard limestone occurs 

 both above and below the Coral Rag. In the Ayton Quarry 

 a boulder of Rhomb-porphyry was noted. 



The remainder of the day was spent in examining the drift 

 deposits near Wykeham, briefly described by Mr. P. F. Kendall, 

 F.G.S., on the circular drawn up for the meeting. 'A great 

 mass of gravel extends from East Ayton to Wykeham, forming 

 a nearly flat-topped terrace, which has been regarded as a beach 

 of the lake, which, in Glacial times, occupied the Vale of 

 Pickering. The gravel contains many pebbles of Jurassic rocks, 

 especially Corallian, and Kimeridge Clay, and a small number of 

 rocks foreign to the district, Granites and Cheviot Porphyrites ; 

 there are also fragments of marine shells, such as Tellina 

 balthica. It is probable that the deposit was laid down along 

 the edge of an ice-lobe which was thrust up the Vale of 

 Pickering as far as Wykeham. The great ridge of gravel which 

 projects out into the low grounds at Wykeham Abbey probably 

 represents a fragment of a terminal moraine.' 



At Yedmandale is an interesting example of a dry valley, of 

 Pre-Glacial age, the entrance to which has been dammed by 

 drift. A gravel pit in the side of this dale yielded Moor Grit 

 and local sandstones in abundance, Scandinavian Porphyrite, 



Naturalist, 



