243 
Having now concluded the examination of fossil shells, Conchylio- 
lithi, I must again say a few words in anticipation of the censures which 
may await me, from those who may think the classification I have 
adopted, with its manifold genera, a too wide and improper deviation 
from that of the great Linnaeus. Had I too have treated of recent 
shells,' a slight deviation might have been sufficient ; but when fossil 
shells are the subjects of our inquiry, this is not sufficient. Few of 
these, comparatively, were known in that classification : many of them 
were even without names, except such as were derived from some 
erroneous notion of their origin ; but, by the classification of Lamarck, 
there hardly remains any among the fossil-shells, whose generic 
situations are not now clearly ascertained. 
LETTER XYI. 
FOSSIL FISH. ...OF VESTENA NUOVA, PAPPENHEIM, MANSFELD, &C.... 
OF ENGLAND. 
T he examination of the various circumstances which offer themselves 
to our observation, whilst contemplating the fossil remains of fishes, 
cannot fail of being highly interesting, and is at the same time very 
likely to throw some light on the mysterious events by which their 
deaths and their subsequent conservation has been effected. 
These curious remains exist in various parts of the world ; but the 
repository most abundant in these fossils appears to be that of the 
mountain Vestena nova, improperly named Monte Bolca. 
This quarry was formerly purchased by the learned Scipio Maffei, 
who spared no pains in acquiring the rich specimens which it yielded. 
In these researches he was assisted by the celebrated Seguier, who 
there formed an inestimable collection, which is now placed in the 
