part 2] LIMESTONK OF rilK l.EICESTERSHIHK COALFIKI,!). lU3 



must hv iiiadu for the ditHculty t'X|H*rieiifeil in (►btainin^ reliable 

 s[>ec*iinen.s from the dolomites ; Imt, even if this allowance be made, 

 the eoral fauna of the Loiisda/ia sub-zone cannot In? described as 

 rich. The bnichioj)od fauna of I).^ in the two districts appears to 

 be very similar; l)ut some sjx'cies, such as Ortliotctrii cf. crcuiatria^ 

 and jKi})ilionaceous Chonefes^ are rarer in the Leieestershire district 

 than they are in the «)ther. Prof. Sibly distinguished certain 

 variations in the faunal facies of the Lonmhilia sub-zone in the 

 Derbyshire district- a i^eneral typical facies developed on the 

 eastern side of the rei^ion, and a more or less h)cal south-western 

 facies with a ])oor coral fauna. The tyjMcal eastern facies includes 

 Lonsdalid JloriJ'onnis, Lithotitrotion Jtmceum, Alveolites neptosa^ 

 and certain Clisi()i)hyUids, none of which is present in the south- 

 western facies. In the typical development, moreover, the brachio- 

 pods do not predominate over the coral fauna. In the south- 

 western area near Waterhouses. the braehiopod fauna is richer 

 than the coral fauna, and the species of Lunsdalia, Li tli oat rot ion, 

 and Alveolites mentioned alnjve are absent, as are the Clisio- 

 ]>hyllids Ili.stioj>lii/1li(in, Rhodojthi/llHin, etc. 



JJoth corals and brachiopods in the Leicestershire fauna sh(»w 

 that it is with the Derbyshire south-western facies that corre- 

 spondence is closest. Thus, in the Leicestershire area, Alveolites 

 septosa has been found oidy at Tieknall, and there it is extremely 

 rare; of honsdalio Jlorifonuis only one specimen has been found 

 at Tieknall, and it is absent from other localities ; Lithostrotion 

 junceum occurs at Tieknall only, and there in beds that are at 

 the top of the Leicestershire D.^-D, sequence. Hist iophyll inn. 

 etc., probably do not occur, althou^j^b the im])ei'fect condition of 

 coral specimens must be borne in mind. 



With rejj^ard to the evidence available from brachiopods, the 

 beds at Hreedon Cloud certainly yield more of these than of 

 corals. Not only, therefore, does D, (especially the Innnerosiis 

 beds) of the Leicestershire area resemble in facies that develojH'd 

 in the south-western ))art of the area examined by Prof. Sibly, 

 but the resemblance is als<» strikinglv marked in the sub-zone 

 of D,. 



3. 1);,' the sub-zone of Ciiathaxoiiiu rKshiuiia. 



in Leicestershin' no typical develo])ment of the J), sub-zone 

 exists, and Ci/fitlm.ronia itself has not been nvonled from Ithe 

 area. 



In the al)sence of the index fossil, thr ai>undanee of sjM'cies 

 common to D.^ and D, su«^ij^ests that the beds yielding this fauna 

 8h<)uld be desiuMiated by the symbol D,-!),. 



A Conipansou of Lithological Features. 



The chief lithological differences and similarities of the Midland 

 se(|uence and that of Leicestershire may be shown conveniently in 

 tiibular form : — 



