406 R. M. Brydone — Zone of faster pilula 



There also the cor-anguimim chalk is practically free from seams of 

 marl, which set in 4 feet below the flint line taken by Dr. Rowe 

 as the base of the Uintacrinus band,' and then continue to occur 

 frequently right up to the quadratu,s zone.) 



I was able to trace Uintacrinus upwards definitely for 40 feet, and 

 13 feet higher I found what appeared to be a plate of it. Eight feet 

 higher I found my first plate (a very smooth one) of Marsupites, and 

 was able to trace plates of 3Iarsupites up to a strong marl seam 



52 feet higher. For a further 16 feet I found small and dwarf 

 brachials, with one or two dwarf Crinoid plates, and Terelratulina 

 Rowei in abundance. These beds by analogy with the Sussex 

 sections I include in the zone of Marsupites. This would give 

 a thickness of 129 feet between the base of the Uintacrinus band 

 and the top of the zone of Marsupites, of which apparently 



53 feet should be definitely assigned to the Uintacrinus band, and 

 68 feet to the zone of Marsupites, leaving 8 feet between them 

 of a relationship at present uncertain. These 8 feet I assign for 

 the present to the Uintacrinus band in conformity with ray treatment 

 of a similar blank area in Hants, thus making a total of 61 feet for 

 the band. 



Having fixed my upper limit of the zone of Marsupites, the next 

 feature likely to be identified is the incoming of 0. pilula at the base 

 of the subzone of abundant 0. pilula. I sought 0. pilula in vain for 

 53 feet of chalk, which carried me on to the concrete platform 

 mentioned by Dr. Eowe. There I found 0. pilula for 1 feet. Then 

 I failed to find it again for 22 feet, which carried me to the edge 

 of the central fall, which entirely obscures, at the foot of the cliff, 

 a thickness of chalk which I made out to be 27 feet, and in which, 

 where accessible in irregular patches higher up, no 0. pilula was 

 found. The first bed to emerge from the fall on its west side is a foot 

 of chalk between two strong marl seams, and in this bed and for 

 a further 13|-feet 0. pilula occurred in abundance. The highest beds 

 of this chalk were visible in reefs standing out of the shingle, and it 

 was easy to see that in the highest 2^ feet the OfFasters were of the 

 exceptional size chai'acteristic of the top of the zone of 0. pilula 

 in Hants and Sussex. It therefore seems certain that the zone of 

 0. pilula of Hants and Sussex is recognizable in Scratchells Bay with 

 an approximate thickness of 53 feet for the lower subzone and 

 74 feet for the upper subzone. 



Above the zone of 0. pilula the zone of Acfinocamax quadratus 

 extended some 200 feet, according to my measurements, to the 

 approximate position of the boundary determined by Dr. E.owe. My 

 measurements are therefore, when summarized — 



feet. 

 Uintacrinus band ......... 61 



Zone of Marsupites ......... 68 



Zones, oi 0. joilula diXid. A. quadratus . . . , , 327 



456 



•^ I have found brachials, and perhaps a plate of Uintacrinus, between this 

 flint line and the marl seam below it, so making the correspondence perfect. 



