HAMSTEAD BEDS. 195 



say whether they represent the White Band, or whether this band 

 should be identified with other white marls at about 120 feet 

 (B. H. 40). Probably the lower bed is more nearly equivalent 

 to the conspicuous seam in the Hamstead Cliff. 



At the southern border of the Forest we meet with a bed that 

 probably corresponds with the Nematvra pupa bed of the coast. 

 This is a stratum full of Cyrena semistriata and Entomostraca 

 (B. H. 43). It is conspicuous over a considerable area, and its 

 position and fossils correspond so well with those of the Nematura 

 pupa bed, that the local absence of the Nematura is counter- 

 balanced by the other evidence. No other band of the sort occurs 

 over the same area, and a bed, apparently on the same horizon, 

 is full of Nematura pvpa at Newport. 



From Forest Side to Gunville the succession is carried on by 

 other borings (B, H. 44 to 52). The first of these is in the same 

 beds as B. II. 43, but as it commences at a higher level there must 

 be a northerly dip of less than 1° between these points. 



About 15 or 20 feet below the Cyrena bed lies a seam of shell 

 marl crowded with Melania muricata and Hydrobia Chasteli This 

 seems to correspond with the similar seam below ihe Nematura pupa 

 bed on the coast. 



About 26 feet lower lies the Black Band, first met with a 

 few yards north of Gunville Bridge (B. H. 49), and again a 

 quarter of a mile further south, in the village (B. H. 51, 52), The 

 section is interesting from its exact correspondence with that seen 

 at Hamstead : — 



Section 1 chain north of Gunville Bridge (B. H. 49). 



Feet. 

 Soil - . - .... 1 



f Blue and gray loam. Nodule, with casts of small univalves 

 j at 4 feet - - - . - - 7 



Hamstead J Lead-coloured clay. Abundant shell fragments {Paludina 

 Beds. ] lenta) and small angular flints between 11 and llf feet 3f 

 I Hard black laminated clay, with shells, pieces of lignite, 

 l_ pyrites, and small angular flints . . . la. 



r Green marly clay, with nmch ' race ' (concretions of carbonate 

 Bembridge J of lime commonly found in weathered marls) and car- 

 Marls. I bonaceous remains like small roots. Crushed Paludina J 

 L Hard green clay •.-----} 



144 



On looking through the series of borings already referred to, it 

 will be seen that the levels and distances have been so arranged 

 that each boring slightly overlaps the preceding one. By this 

 means the whole succession of strata has been penetrated, and we 

 can construct a section of the Hamstead Series comparable with 

 that seen in the cliff at Hamstead. 



The total thickness of the Hamstead Series on the south side 

 qf Parkhurst Forest appears to be 220 feet. This calculation 

 was made liefore the re-measurement of the typical locality, and 

 it is interesting to find that it agrees thoroughly with the corrected 

 thickness. 1 he highest strata in Parkhurst Forest are extremely 



N 2 



