Yol. 52.] A DELIMITATION OF THE CENOMANTAN. 113 



representative of the Gault. The following is a condensed view of 

 the beds which compose this stage in Whitecliff: — 



Feet. 



Hard calcareous sandstone, few fossils 8 



Yellowish sand and sandstone, with numerous layers of chert ... 56 



Bark green sand and hard glauconitic stone 4 



Green, grey, and purple sand, with layers and concretions of hard 



calcareous sandstone 70 



Dark green argillaceous sand seen for 15 



153 



The beds at the junction of the Chalk and Green sand may be fol- 

 lowed along the foot of the magnificent range of cliffs which extends 

 from Beer Harbour to Beer Head, and near that headland the zone of 

 Ammonites Mantelli can be seen to thicken out rapidly, the thicken- 

 ing being chiefly produced by the addition of material to its lower 

 bed, till at Beer Head the whole is about 14 feet thick, and is very 

 clearly divisible into two parts or beds. The upper bed, 2| feet 

 thick, is a rough quartziferous limestone with layers of green-coated 

 nodules > and in it Holaster subglobosus is common ; the lower bed is 

 in its higher part a hard shelly and gritty limestone, with Pecten 

 subinterstriatus, P. asper, Ammonites Mantelli, Rliynchonella 

 dimidiata, Pseudodiadema variolar e, and many other fossils ; in 

 this higher part the grains of quartz and glauconite are small, but 

 in the lower 5 feet the former are large and the rock becomes a 

 rough and coarse calcareous grit, in which the most abundant fossil 

 is the large, branching, coral-like Ceriopora ramulosa. The plane of 

 division between its base and the Upper Greensand below is well 

 marked. 



These two beds include Mr. Meyer's beds 10, 11, 12, but there is 

 no clear representative of his 13, the glauconitic chalk or marly 

 greensand, though there are patches and nests of such sand at the 

 base of the overlying chalky limestone (Turonian). 



We now come to the place where these beds attain their greatest 

 development ; this is in the great Southern-down landslip, and in 

 the cliff from which it was detached, known as Hooken Cliff. Here 

 the zone of Ammonites Mantelli is 24 feet thick, and the succession 

 is as follows : — 



Feet. 

 '6. Hard, rough, nodular chalk, glauconitic at base ... 7 

 5. Greenish, sandy, glauconitic marl, with a few brown 

 phosphate-nodules in the lower part ; Rhyncho- 



nella Wiestii, Belemniiella plena, etc 6 



f 4. Layer of brownish green-coated nodules at top of 

 hard, rough, nodular limestone, passing down into 

 ' white gritty limestone with Holaster subglobosus . 6 



7o | 3. Hard, rough, nodular layer with phosphatic matter, 



passing down into hard shelly and sandy lime- 

 stone with Pecten asper and many other fossils ; 

 the quartz-grains getting larger in the lower part, 

 and the rock passing into a coarse calcareous 



sandstone with ' corals ' 18 



Upper Green- f 2. Even-grained calcareous sandstone with few or no 



SAND. 1 fossils ? 



Turonian. 



Amm. Mantelli. 



