372 



C. PAEKIISTSON ON THE ISLE-OF-WIGHT 



And suddenly as this horizon appears, so it disappears, the succeed- 

 ing 32 feet being identical with the sands below in lithological cha- 

 racter, with the exception of being less hard and gradually getting 

 lighter in colour as we follow it up the section. Organic remains are 

 few and far between, Holaster Icevis (on the authority of Dr. Wright, 

 P.R.S.) being the only distinctive fossil. Up to this point the 

 fauna may fairly be said to belong to the same epoch ; and collections 

 from the lower division should be kept separate from those from the 

 upper cherts and rags, which we now come to, and which indicate 

 different conditions of life. The red sands give place to alternate 

 bands of hard chert and coarse greensands {vide section). In the 

 6 feet of inferior building-stone A. rostratus attains its greatest 

 development, and casts of large Nautili are common. This is divided 

 from the building-freestone (which hardens on exposure to the at- 

 mosphere) by one foot of blue chert, having another chert band on 

 the top little else but a mass of sponge-spicules imbedded in siliceous 

 matrix. In the next bed of Greensand Peat en orbicularis is plentiful, 

 though by no means confined to that band. Pecten inter striatus is 

 not uncommon on the exposed surface of the succeeding Chert band, 

 and species of Lima in other bands which could not be identified 

 with certainty. The fossils may not all be confined to the various 

 beds. Pecten asper, Lamk., never occurs in the Isle of Wight in 

 these Cherts or Greensands ; it is confined to a bed of pkosphatic 

 nodules in the Chloritic Marl, but is probably derived from older 

 rocks, being in most cases much crushed and broken. 



The following fossils are from the Upper Chert and Eag beds : — 



Siphonia pyriformis, Park. 

 Nautilus elegans, Sow. 

 sp. 



Lima, large sp., strong ribs. 

 Pecten, 14 ribs, (Galliennei ?). 

 Cardium sp. 

 Holaster sp. 



Ammonites rostratus, Sow. 

 Olathraria Lyellii, Mant. 



Exogyra conica, Sow'. 

 Ostrea frons, Park. 

 Lima aspera, Sow. 

 Ostrea vesiculosa, Soy;. 

 Cucullgea glabra, Park. 

 Pecten orbicularis, Sow. 



interstriatus, Lezon. 



5-costatus, Sow. 



sp. 



The Cycadeous plant Glathraria Lyellii was first noted by 

 Man tell, who obtained his specimen from a quarryman in Bon- 

 church ; it was not obtained from the Chalk Marl, but from the 

 Greensand Hags. A second specimen of this rare fossil was found 

 at Steephill, near Yentnor, last winter, 10 feet below the Chloritic 

 Marl, in the same bed as the former one. The remains consist of the 

 top of the stem surrounded by petioles or leaf-stalks, the leaves them- 

 selves being either shed or decayed. It has usually been considered 

 a plant of Wealden age. If, however, island floras and faunas can be 

 shown to have existed during the formation of the Greensand strata, 

 both Chelonia and remains of plant-life are at once accounted for. 



The Chloritic or Glauconitic Marl, lying immediately over the 

 Greensand, may be traced along the escarpment of the Undercliff, 

 from Blackgang to Luccombe, cropping out finally near Culver Cliff. 

 It varies in thickness from 6 to 7 feet, and may be divided into two 



