LOWER ESTUARINE SERIES. 319 



near Goathland, which yields Nucula, Asiarte minijna, etc.^ This 

 bed is about 1 5 feet thick. 



Mr. Hudleston observes that the group thins out towards the 

 south and west of the Oolitic area ; it, however, constitutes a large 

 portion of the Staintondale Cliffs, where, in certain layers of 

 nodular ironstone, many species of ferns are nicely preserved.^ 

 The beds appear in the cliffs from Robin Hood's Bay to Huntcliff ; 

 and they may be studied at Whitby and Blue Wyke. 



The ' Great Sandrock,' 50 to 100 feet, occurs at or near the base of the series : 

 it is largely used for building-stone. Whitby Abbey was constructed of this stone, 

 which has been worked for building-purposes in Eskdale. A coal-seam was 

 formerly worked to the north of Yearsley and Grimston Moors. Cement-stone 

 (hydraulic limestone) has been burnt for lime at Terrington. Ironstones have been 

 worked at Kirkham and Mount Pleasant, near Castle Howard. 



Millepore Series. 



This series of beds, so named by Dr. Wright, from the occurrence 

 of Cricopora {Millcpom or Spiropora) straminca, occurs as an impure 

 limestone in Gristhorpe Bay ; nearer Scarborough it is obliquely 

 laminated and arenaceous, and it is still more sandy at Cloughton 

 Wyke. In places the rock is oolitic ; and the characteristic fossil 

 PoJyzoon is displayed on the weathered surfaces of the beds. Dr. 

 Wright correlates the Whitwell oolitic limestones of the Howardian 

 Hills with this series, which is from 8 to 30 feet in thickness. It 

 may be seen also at Osgodby. It is continued in the Cave Oolite 

 and Lincolnshire Limestone, and, as Mr. Hudleston considers, 

 may therefore, with the Whitwell and Cram Beck Limestone, be 

 the chief representative of the Inferior Oolite in Yorkshire. 



The beds yield Lima dupUcata, \Gervillia Hartmaiuii, G. lala, 

 Modiola tnibricata, Trigonia relicosta, T. conjungens. Pinna cuneafa, 

 Ceromya Bajociana, Myacites recurva, Cardium Buckmani, Isocardia 

 cordata, Tcrehratida submaxillafa, and Pygaster scmisidcatus. Most 

 of the fossils have been obtained from Sycarham, near Cloughton 

 Wyke. Natica cincta, which occurs here, is also found in the Oolite 

 Marl of the Cotteswolds. Pleuroiomaria, which is abundant in the 

 South of England, is comparatively rare in Yorkshire. At Sycarham 

 the rock is a ferruginous grit seen in reefs along the shore, and 

 it contains Kaolinite.* Mr. Hudleston has traced the Millepore 

 Bed near Goathland, otherv/ise the Middle and Lower Estuarine 

 Series are not separable in parts of north-east Yorkshire. 



Middle Estuarine Series. 



This group, known as the Middle Shale and Sandstone, consists 

 of shales and sandstones (Block Sand rock), from about 30 to 100 



1 G. Mag. 1877, p. 552; Explanation of Quarter-Sheet 95 N.W. (Geol. Survey), 

 p. 33 ; 96 N.E. p. 29. 



2 P. Geol. Assoc, iii. 307 ; J. Phillips, Q. J. xvi. 119. 

 ^ Hudleston, G. Mag. 1882, p. 147. 



