io8 Sheppard : The Mdkiiig of East Yorkshire. 



to such a larg-e extent for alum and jet. The alum works at 

 Boulby necessitated excavations of enormous dimensions, during- 

 which many strang-e animals with long- necks and jaws (and 

 almost as long names !) were discovered. If a bed of shale be 

 examined carefully it w^ill be found to consist of minute particles 

 of mud or sediment which at one time were deposited in a com- 

 paratively shallow sea. It is suggested that the edges of that 

 sea consisted of cliffs containing coal measures, the denudation 

 of which gave the Liassic shales their dark colour. The bands 

 of Liassic limestone are renowned commercially for their purity, 

 and to the student of nature they have many points of interest. 

 The}- contain more completely than do the adjoining shale beds 

 the remains of the inhabitants of the Liassic sea, and indicate 

 the probable conditions which existed during the time they were 

 in process of formation. Here a layer will be found to consist 

 entirely of Oyster shells — a fossil oyster bed, in fact. There, the 

 remains of strange Mollusca, Ammonites and Belemnites, abound 

 in thousands. Another bed will be largely composed of the 

 stems of Encrinites or Sea Lilies ; still another is made up of the 

 fragments of all of these, whilst here and there a complete 

 skeleton or the dismembered remains of an enormious Fish-lizard 

 lie buried. Reasoning from the present to the past, and bearing 

 in mind the nature of the deposits in modern seas and oceans, 

 and the org-anic remains therein found, it is not difficult to 

 assume what w^as the condition of things prevailing whilst the 

 rocks around Whitby were being formed. The Oysters in the 

 oyster-bed are not precisely the same as those living at Clee- 

 thorpes to-day, but they are sufficiently near in general 

 resemblance to impress even a novice with the fact that they 

 probably thrived in somewhat similar surrounding's. The time 

 is now gone when the organic remains in our quarries and cliffs 

 w^ere considered to be, as Wordsworth puts it, 



' The sport of Nature, aided by blind chance, 

 Rudely to mock the works of toiling- man." 



The Ammonites so characteristic of the Whitby cliffs are no 

 longer looked upon as * Snakes which w^ere turned into a coil 

 of stone, when holy Hilda prayed.' Naturalists have convinced 

 us that the Ammonite, like the living Nautilus, was once a 

 denizen of the seas, and crawled on the sea floor or floated on 

 the top at will, by means of its ' siphuncle ' and chambers. We 

 have left to us the Nautilus in our seas to-day, and it may be 

 noted that the same genus was living, in company with the 

 Ammonite, in the old Liassic waters. The Anmionite appears 



Natur.ilist, 



