230 



the other series above and below, Avhich have yielded the largest 

 number and the most pei'fect specimens of Bajocian Plants. Fossil 

 plants are, however, difficult to determine, and it is probable that 

 some so-called species are merely variant forms of one and the same 

 species. Two species of marine fucoids have been recorded from 

 these beds. 



The Upper Estviarine series is more shaly than either of the 

 other series. It includes, however, a few irregular bands of sand- 

 stone, and one or more beds of granular ironstone, and rests upon 

 a massive bed of sandstone known as the " Moor Grit." From the 

 sandstones in the lower portion of the series 1 1 species of plants 

 have been obtained at White Nab, Ked Cliff, Scalby and North 

 Bay, Scarborough. About half of these are common to the ]\Iiddle 

 Estuarines. There are, however, in regard to these Yorkshire 

 Bajocian Plants, so many doul)tful identifications, and at the same 

 time so much lack of certainty as to the precise horizon from which 

 certain specimens were obtained, that the whole question needs 

 careful re-investigation in the light of present day knowledge. 



Some years ago my friend, Mr. J. M. ^leek, of Redcar, brought 

 for my inspection some specimens of Tamiopteri'^, Wil/iamsonia, 

 and other plants Avhich he had obtained from the Old Marske 

 quarry. Early in 1902 he very kindly took me to the 

 place from which he had obtained his specimens. Since that date 

 I have repeatedly visited the place, having oljtained the sanction of 

 Lord Zetland's Agent to investigate there, and with the valuable 

 assistance of Mr. P. Huntington, Master of Ingleby Greenhow 

 School, I have obtained hundreds of specimens. Many of these 

 are in a tine state of preservation, and occur in a fissile ironstone, 

 of Avhich I have obtained the following analysis through the 

 kindness of ]\Jr. J. J. Burton : — 



Total Iron (Fe) 42-90 per cent. 



Peroxide of Iron (Fe„ O,) 61 -28 



Ferric Oxide (Fe O) Nil 



Silica (Si O.,) 15-30 



Manganous Oxide (Mn O) ... ... "65 „ 



Alumina (AI2 O,) 4 88 



Lime(CaO) 2-10 



Magnesia (Mg O) MS 



Phosphoric Acid (P,> O5) 2-38 



Sulphur Trioxide (S O3) -16 



Combined Water and Organic Matter... 12-20 „ 



10010 



