To ROBERT BRIDGES, M. D.. 



My Dear Ekiend ; 



Your iiauio has been so long associated with the progress of the Natural 



Sciences of our country, and particularly in connection with the advancement of our Academy, in 



which you have done so much and so well, towards promoting its objects, that it is with peculiar 



pleasure, more particularly as it gratifies at the same time my warm personal feeling, that I offer 



this volume to you, sincerely wishing that our institution may long have the advantage of your 



inestimable services. 



Very truly and very sincerely yoiu's, 



ISAAC LEA, LL. D. 



