tVl; ; -; .PREFACE TO* THE SEVENTH EDITION. 



Miss E. M. Shinnie, Miss Alice M. Davidson, and the lat 

 Mr. George Davidson. In almost every case the illustn 

 tions have been derived from original memoirs an 

 works of reference, or drawn from specimens. 



J. A. T. 



THE UNIVERSITY, 



ABERDEEN, October 1920. 



