Vol. 52.] IN YOKKSHIRE AND LINCOLNSHIRE. . 213 



clear sections, only the broader features of its relationship can be 

 demonstrated. 



In both areas the uppermost beds of the series pass upward into 

 the Red Chalk. 



The correlation of the typical sections of each district is illustrated 

 in the diagram facing the opposite page. 



VI. The Age or the Belemnites lateralis Beds. 



The definite purpose of my paper was to bring out anew, and to 

 place on a more satisfactory basis, the relationship of the strata 

 underlying the Chalk in Yorkshire and Lincolnshire, and I venture 

 to hope that in the preceding pages this has been accomplished. As 

 for the broader issues to which this work gives rise, I think they 

 may for the most part await with advantage the accumulation of 

 fuller and more accurate information on many points. In England 

 there is still much to be done, both in the study of the palaeonto- 

 logical material already collected, and in the re-examination, in the 

 light of the new evidence, of the region lying to the southward of 

 that herein discussed. In the Eastern Midlands at least some 

 portion of the fauna of the Speeton Series (including Belemnites 

 (lateralis) subquadratus) is preserved in some of the phosphatic- 

 nodule beds, but whether in an original or derivative form is still 

 uncertain. In several regions abroad also, and especially in Germany, 

 the information which we possess regarding the corresponding strata 

 is at present conflicting and insufficient, and will undoubtedly be 

 considerably affected by researches which are now in progress. I 

 had indeed hoped that my esteemed friend Prof. Pavlow would have 

 been able to lay before the Society on this occasion a resume of the 

 available facts respecting the Continental equivalents of the series. 

 But Prof. Pavlow has at the last moment, from physical indis- 

 position, found it impossible to complete his notes in time. We 

 may hope, however, that he will shortly be able to bring forward 

 his valuable contribution on the subject. 1 Meanwhile I think that 

 a brief recapitulation of the work already published, bearing on the 

 disputed question of the age of the Zone of Belemnites lateralis, will 

 form a fitting conclusion to this paper. 



Leckenby seems to have been the first definitely to formulate 

 the view that the lowest part of the Speeton Clay should be classed 

 as Jurassic, basing his opinion mainly on the occurrence therein of 

 coronated ammonites of the Gravesianus-type. 2 These ammonites 

 were afterwards supposed by Prof. Judd to have been obtained 

 from beds capping the Upper Kimeridge shale, but below the clays 

 with Belemnites lateralis. 3 In my former paper, however, I was 



1 [While this paper was passing through the press, the communication 

 of Prof. Pavlow above referred to, ' On the Classification of the Strata between 

 the Kimeridgian and Aptian,' was read, and its publication may be looked for 

 in a subsequent number of the Journal. — April 22nd, 1896.] 



2 See note by J. Leckenby in Dr. T. Wright's Monogr. 'Brit. Cret. Echinod.,' 

 Pal. Soc. vol. xxi. pt. i. p. 9. 



3 'On the Speeton Clay,' Quart. Journ. Geol. Soc. vol. xxiv. (18(58) p. 2?8. 



q2 



