PREFACE 



for the use of certain drawings of fossils belonging to the latter institn- 

 tion. and to Dr. W. H. Dall. of the Smithsonian Institution, both for 

 access so freely given at all times to the collections of the IsTational Museum 

 and especially for his frequent valuable personal assistance and sugges- 

 tion. The author is, however, alone to be held responsible for the 

 opinions expressed herein. 



L. C. Glenj^. 



February 8, 1904. 



