WATSON— NOT-ES ON METALLIFEROUS SADDLES, 



357 



tails of crayfish.. At last, however, appeared in 1724 the celebrated 

 dissertation of Ehrhart on the Belemnites of Franconia, in which he 

 demonstrated 



1st That they were parts of marine animals allied to the ISTautili 

 and Spirulss ; hence he perceived the affinity between the alveolus 

 and the body of the Belemnite. 



2nd That they grew or were enlarged by the application of ex- 

 ternal layers of animal-matter. And 



3rdly That their chemical composition was indicative of an 

 organized body. 



And these points he rendered more intelligible and evident in his 

 second edition (1727) by a plate of figures. 



(To he continued.) 



NOTES ON THE METALLIFEROUS SADDLES, OR ORE- 

 BEARING BEDS IN THE CONTORTED STRATA OF THE 

 LOWER CARBONIFEROUS ROCKS OF CERTAIN PARTS 

 OF DERBYSHIRE AND NORTH STAFFORDSHIRE. 



By Dr. Joseph J. W. Watson, F.G.S., F.S.A., etc.. Member of the 

 North of England Institute of Mining Engineers. 



The inferior division of the Carboniferous series in Derbyshire and 

 North Stafibrdshire, composed of calcareous rocks and shales, and 

 forming the Mountain Limestone group of those counties, presents, 

 particularly about the neighbourhood of Alstonfield, some very 

 interesting and remarkable associations of metallic minerals with 

 certain mechanical disturbances of the strata ; moreover, these asso- 

 ciations are not to be indiscriminately classed with the general phe- 

 nomena of the mineral veins of the districts in question, but must be 

 considered as special facts requiring a separate consideration and 

 explanation. Their existence is no new discovery, since they have 

 been recognized from the earliest times that mines have been worked 

 in the places where they occur, and where also they are at most 

 times regarded as valuable features, inasmuch as the richest deposits 

 of ore have been found in connection with them ; indeed, so decidedly 

 has this been the case, that, in working the mines, much of the 

 futm*e success has been calculated by the amount of probability of 

 any particular vein intersecting the disturbed beds ; such unions 



