IfOTES ON THE LIAS 13^ THE NEIGHBOURHOOD OF HADSTOCE:. 177 



The remaining beds of the M. Lias are yellowish iron-shot 

 limestone, the little grains of yellow ochre, producing an oolitic 

 appearance, and at first sight the beds might easily be mistaken 

 for some in the Jurassic series. They are not regularly bedded 

 and separated by partings like the L. Lias, but are more or less 

 massive, and break up into irregular blocks. The Ammonites we 

 have obtained in situ are A. Jamesoni, latecostatus, and Henleyi; 

 hence the Jamesoni zone is represented as well as the Armatus 

 zone. The order in which the Ammonites occur is therefore 

 normal, but it seems impossible to draw hard and fast lines; the 

 zones blend into one another, the species overlapping in a more 

 marked way than when the deposits are less condensed. Even at 

 Charmouth where the M. Lias is so thick, Mr. Day has remarked 

 (Q.J.G.S. p. 296) on the great range of some Ammonites, e. g. 

 A. fimhriatus passes up through some hundreds of feet. I fancy 

 that extended observations and increased acquaintance with the 

 contents of strata, will tend to modify our somewhat crude way 

 of drawing hard and fast lines. Mr. Moore's observations seem 

 to me to have an especial value in this respect. 



The Brachiopoda found in situ here are To elratula numismalis 

 and RhyyicJioneUa rimosa : we have not noticed these species at all 

 in the L. Lias, and consider them therefore confined to the 

 M. Lias round Eadstock. As we meet with other species we 

 shall return again to the subject of the range of the Brachiopoda. 



Below the M, Lias is seen the Spiriferina clay with its 

 phosphatic concretions and the same fossils as in the other sections, 

 — only the most fossiliferous lower portion is here present. 



The Middle Lias forms the top of the quarry as we have seen, 

 but on the map of the Geological Survey it is coloured as Lower 

 Lias. Even in the new edition of sheet 19, which bears the 

 names of some of the most distingiushed officers of the survey, we 

 notice this anomaly. In one part of the map the M. Lias has 

 been recognised and distinguished by a separate colour, but in the 

 Eadstock district it has been confounded with the L. Lias. This 

 is more or less of a defect, and would have been obviated by a 



