1850.] 



PRESTWICH ON THE LOWER TERTIARY STRATA. 



269 



Cardiura nitens, Sow. 



Plumsteadiense, Sow. 



, n. sp. a. 



Cytherea ovalis, var. ? Sow. 



Proceeding by Uxbridge to Watford, occasional imperfect indications 

 of this bed are met with. On the Birmingham Railway, at Bushey 

 near Watford, the mottled clays with the basement bed of the Lon- 

 don clay were exposed, in a section which I was too late to see in a 

 good condition. The superposition, however, was sufficiently appa- 

 rent. The following organic remains were found there by the late 

 Dr. James Mitchell :— 



Cytherea obliqua, Desk. 



Nucula. 



Panopsea intermedia, Sow. 



Rostellaria Sowerbyi, Mant. 



Diverging five miles to the south, the chalk comes so near to the 

 surface in the valley at Pinner near Harrow, that it is worked by 

 shafts sunk through the superincumbent tertiaries. The followino- 

 is a section of one of these shafts. (See fig. 14.) ° 



Fig. 14. — Section at Pinner. 



h London clay. 



1. Large tabular septaria. 2. Sands 3 

 Pebble bed. 



^d. Mottled clays (1 and 2) with a few subordi- 

 nate beds of sands (3). 4. Impure 

 green sands with green- coated flints. 



Chalk. 





The works were not in operation at the time I visited this spot, and 

 I was unable to procure any of the fossils said to occur abundantly 

 in the stratum which I have marked " c. 1." 



Passing eastward by Shenley Hill, no good section of this bed 

 occurs until we reach a brick-field one mile east-south-east of Hat- 

 field, and immediately adjoining the east side of Lord Sahsbury's 

 park. This pit exposes a complete section from the lower part of 



