WATSON — NOTES ON JI KTAUjIFHUOUS SADULKS. 
357 
tails of crayfish. At last, however, appeared in 1724 the celebrated 
dissertation of Elu-hart on the Belemnites of Franconia, in which he 
demonstrated 
1st That they were parts of marine animals allied to the NautiH 
and Spirulaj ; hence he perceived the affinity between the alveolus 
and the body of the Belemnitc. 
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 figaires. 
(.To be 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. JosErn J. W. Watson, F.G.S., F.S.A., etc.. Member of the 
North of Eng-land Institute of Mining- Engineers. 
The inferior division of the Carboniferous series in Derbyshire and 
North Staffordshire, composed of calcareous rocks and shales, and 
fomiing the Mountain Limestone gToup 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 jDlaces 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 ease, that, in working the mines, much of the 
future success has been calculated by the amount of probability of 
any particular vein intersecting the disturbed beds ; such unions 
