54 GEOLOGY OF THE ISLE OF WIGHT. 



The nodules and fossils referred to above occur in three to four 

 feet of sand, which form the top only of the Folkestone Beds. 

 This sand, wliicli both passes up into, and possesses this paljeonto- 

 logical affinity with the Uault, seems to be an expanded repre- 

 sentative of the grit-band of Midhurst and Pulborough, which 

 also passes up into the Gaulr. The grit-band, as before explained, 

 is sharply marked off from the underlying mass of the Folkestone 

 Beds ; if the sand witli Gault fossils could also be separated from 

 the Folkestone Beds, we should no longer have to face the anomaly 

 of the upper member of the Neocomian group being characterised 

 by a Gault fauna, and should also be able to point in the Wealden 

 area to a basement-bed to the Gault corresponding to the 

 Carstone of the Isle of Wight. At present, however, it must 

 remain uncertain whether an upper portion of the Folkestone 

 Beds can be separated off, as on equivalent to the Carstone of the 

 Isle of AVight, or whether the Carstone changes horizontally into 

 a sand of the usual Folkestone Beds type during its passage north- 

 eastwards below the Hampshire Basin. 



The fossils of the Carstone of the Isle of Wight, so far as they 

 go, indicate as close a relationship with the Upper Neocomian as 

 with the Gault. Two forms, however, occur which are not known 

 below the Folkestone Beds, viz., Lima parallela, Sow., which 

 .ranges through the Gault, and Ammonites Beudantii, Brong., 

 which occurs in the A. mammillaris zone both in England and 

 France, as well as in the zone between the Upper and Lower 

 Gault, to which it gives its name. The following is the complete 

 list :— 



Fossils of the Carstone. 



Wood (Bonchurcli and Dunnose), 



Echinoderm, fragment (Bonchurch). 



Enallaster (Hemipneustes) Fittoni, Forbes: as a pebble (Bonchurcli). 



Crustacean fragment (Bonchurch). 



Hoploparia longimana. Sow. (Sandown and Dunnose). 



Avicula (Bonchurch and Blackgang). 



Astarte (Sandown). 



Cardium (Bonchurch and Sandown). 



Exogyra (Sandown and Blackgang). 



Leda scapha?, D'Orh. (Sandown). 



Lima (Blackgang). 



Lima parallela, Sow. (Blackgang). 



Nucula (Blackgang). 



Panopsea? (Fitton, Blackgang). 



Fecten orbicularis, Soiv. (Bonchurch, Dunnose, Sandown, Blackgang 



Pecten quinquecostatus. Sow. (Sandown). 



Plicatula carteroniana, D'Orh. (Sandown). 



Tellina (Sandown). 



Venus? (Fitton, Blackgang). 



Actaeon (Sandown). 



Pleurotomaria (Blackgang). 



Solarium (Forbes, Blackgang). 



Trochus (Bonchurch). 



Ammonites, fragment (Blackgang). 



,, Beudantii, Bronrj. (Blackgang). 



Lamna, tooth of (Dunnose). 



