I860.] WEIGHT— MAS. 395 



In these two sections the White Lias represents the zone of 

 Ammonites planorbis, and the beds above, from the " lied size " 

 upwards, the zone of Ammonites Buddandi, consisting of alternate 

 beds of limestone and marl, which have received special names from 

 the "workmen. Fragments of large Ammonites are sometimes found 

 in these beds. I collected Lima gig antea, Sow.,Z;ma antiquata, Sow., 

 and an Ostrea. 



At Pinhay Bay the clays above the White Lias contain numerous 

 spines of Sea-urchins, and some tests with spines attached. I know 

 the following Echinodermata from this bed : Cidaris Edwards!!, 

 Wright, Pseudo-diadema lobatum, Wright, Hemipedina Bechei, Bro- 

 derip, Hemipedina Bowerbankii, Wright, 



Nearly all the Echinidte of the Lias at Lyme are found in this bed 

 of marl at low-water, after its surface has been exposed at spring- 

 tides. 



Localities of the Ammonites planorbis beds. — In Gloucestershire 

 this zone is well exposed at Brockeridge Common. My friend Mr. J. 

 Jones informs me that he has found it at Wainlode, in a quarry on the 

 right-hand side of the road to Gloucester, ascending the hill from the 

 inn; — between Hartpury and Ashelworth, where he found Am. pla- 

 norbis in a brownish-blue clay, which split into thin laminaj and 

 contained numerous impressions of this shell ; — at Elmore, in quarries 

 near the Old Kennel, in a light-coloured clay, and in one of the lower 

 bands of claystone. 



In Glamorganshire, it is seen in the fine coast-section at Penarth 

 Head (see page 381). In Somersetshire, in the cutting of the Great 

 Western Railway at Saltford (p. 399) ; in the Uphill Cutting on the 

 Bristol and Exeter Railway (p. 382) ; in the coast-section at Watchct 

 (]). 384) ; and in all the quarries at Street (p. 390), where it forms 

 the top beds. 



In Worcestershire it is found at Strensham (p. 393) ; and in War- 

 wickshire at Binton (p. 394), Grafton, and Wilmcote (p. 386). 



It is likewise found at Robin Hood's Bay on the coast of York- 

 shire ; the beds hero lie below low-water mark ; but large blocks, 

 frequently washed up by the tide, are literally crowded with Ammo- 

 nites planorbis, known at Scarborough and Whitby as Am. erugatus, 

 Bean. 



The coral-bed at Lussay, Isle of Bkye*, probably represents this 



Am. jdinuirb'is zone, as I found the same species aB the llel>rideau 



coral in the light-colonred clays with Am. i>iiht<>ri<!* at Street. 



This lowest Ammonite-zone has. therefore, a wide geographical 

 distribution throughout the Lower Lias of the Northern, Midland, and 



Southern Counties of Knglaiid, and it retains the same relative posi- 

 tion in tin Lower Lias of France, Germany, and Switzerland. 

 Fossils of /!>• Ammonites planorbis beds.— 1 The fauna of this zone 



is very limited : at presenl I knOW only the following species ; — 



PlegJoaaoroH Bawkinsii, ( ;/ f >. 



Etheridgu, // ■• '■ 



Ichthyosaurus intermedins, ' 

 tenuirostris, ' 



communis. Oottyb, 





* Quart .Tipuru. GfooL Soft toL riv. pp. I & 34. 



