VI PREFACE. 



the more advanced inquirer ; but sufficient, it is 

 hoped, will be introduced to enable the student 

 to detect the more decided and more important 

 characters of these substances, and to place them 

 under their appropriate genera. 



It may, it is hoped, thus become a useful 

 vade-mecum for the intelligent traveller who may 

 not yet have attended to these inquiries. At 

 present, disappointment frequently occurs, from 

 the too limited accounts of the fossil remains 

 which offer themselves for examination in dif- 

 ferent parts of the world. The observer is 

 perhaps satisfied, for instance, vi^ith stating that 

 the rocks were found to contain the remains of 

 shells, and that these remains were chiefly of 

 bivalves or of univalves ; when, by a little 

 farther investig^ation of even the fras^ments of 

 these fossils, aided by reference to a manual of 

 this kind, their genera might have been ascer- 

 tained. Such marks might also be noted, as, 

 by subsequent comparison with the more cor- 

 rect and elaborate labours of Lamarck, Sowerby, 

 &c. would admit of their species being deter- 



