162 F. L. Kitchin & J. Pringle — TJie Upiiey" Qault in 



' At Lulworth Cove, where the Gault rests with a marked surface 

 of erosion on the Wealden Beds, we found only the comraon lamelli- 

 branchs which characterize the lower beds in the neighbouring 

 sections to the west and at Holworth House. At both sides of the 

 cove the exposures were poor and overgrown. A better section was 

 seen furthet west at the east end of the bay at Dungy Head, east 

 of DUrdle Door. Here, again, we noticed the great rarity of 

 amnaonites and the general paucity of distinctive fossils in the lowest 

 beds. . The dark silty clay about 10 feet above the base yielded a few 

 lamellibranchs, such as Nucula pectinata J. Sow., Pecten 

 {Syncyclonema) orbicularis J. Sow., and Lima [Mantellum) gaultina 

 Woods, as well as Serpula concava (J. Sow.), which is common in the 

 rostratus-heds of Upper Greensand facies. Only one poor fragment 

 of an ammonite was obtained, one of the species commonly 

 designated HojMtes splendens, and apparently a form identical with 

 one occurring in Bed IX at Folkestone and with the equivalent fauna 

 ait Heath, in Bedfordshire. At about 25 feet above the base, in a dark 

 glauconitic clayey sand, we found numeious casts of lamellibranchs, 

 including Inoceramus sulcatus Parkinson. So far as we were able 

 to examine the beds above this point, there was agreement with 

 the section as given by Professor Barrois. Lithologically and. 

 paleeontologically, the silty and sandy Gault here forms a unit with 

 the '■ Upper Greensand " above, into which it merges almost 

 imperceptibly ; and we see no reason to believe that the Lower Gault 

 has any representation along this coast. 



Near White Nothe, the overlap of the Gault on to Portland and 

 Kimmeridge beds is displayed in a remarkable section.^ We found 

 the lowest bed of the transgressive strata to be a dark brownish 

 green, gritty and clayey sand, containing pebbles of Portland 

 limestone and quartzite at the base and showing ochreous weathering. 

 The few feet of this bed yielded no fossils. The succeeding stratum, 

 a soft, bluish silty micaceous clay, about 6 feet in thickness, seemed 

 also to be almost barren of organic remains. Above this we were 

 able to examine the beds at intervals upwards through a thickness 

 of about 30 feet or rather more. In the lower part there occurred 

 Inoceramus concentricus Parkinson. At higher levels there were 

 numerous lamellibranchs, such as Exogyra conica J. de C. Sow. and 

 species of Panopea, Pinna, Pecten, and the Mantellum mentioned 

 Srbove. This last species was conspicuously abundant, the valves 

 attaining a large size in the upper part of these beds. There were 

 also numerous crushed examples of a Turritella-like gastropod. 

 The whole aspect of this fauna shows an approach to the facies of 

 the Blackdown Greensand, of more markedly littoral character. 

 AJbove this the section is obscured for some distance by talus. The 

 succeeding beds of " Upper Greensand " type, yielding casts of 

 ammonites of the rostratus-iauna, together with many lamellibranchs, 



-* A. Strahan, "The Geology of the Isle of Purbeck and Weymouth": 

 Hem. Geol. Surv., 1898, pp. 155-8. . 



