PRBFACB. 



In presenting this little volume to the public, a word or two 

 in explanation of the circumstances which gave it birth may not be 

 deemed inappropriate. The author had originally intended 

 making a little pamphlet covering some of the more interesting 

 experiences of the Mexican Expedition. It has been thought, 

 however, that the important nature of the expedition and the 

 linking together of narrative, science, and history (a combination 

 not often attempted by authors) were circumstances sufficient to 

 justify its publication in a more pretentious form. 



The tour which forms its subject was undert9.ken under the 

 auspices of the Academy of Natural Sciences of Philadelphia, the 

 author acting as Zoologist. The expedition was under the leader- 

 ship of Professor Angelo Heilprin, Curator-in-charge of the 

 Philadelphia Academy, and its object was to collect data and 

 specimens illustrating the fauna, flora, and Geology of Yucatan 

 and Southern Mexico, with a consideration of the high mountain 

 peaks of the Mexican Plateau. For full accounts concerning the 

 scientific portion of the expedition, the reader is lespectfully 

 referred to the Proceedings of the above Academy from 1890 to 1895. 



The illustrations used are mostly from photographs taken by 

 the party, together with sketches made by the author. The 

 majority of new species of mollusks discovered by the expedition 

 are figured in the following pages. 



As to the literary character of the work, if not so good as might 

 be wished, it is yet such as circumstances have permitted. The 

 text has been written during the leisure hours of a busy pro- 

 fessional life, which fact will explain, if it does not excuse, its 

 errors. The author has endeavored to picture the scenes which 

 came under his observation, as they appeared to him. 



The author desires to express his gratitude to the friends, 

 both in Mexico and the United States, who have in various ways 

 assisted him. He trusts that this little sketch of a naturalists 

 experiences may awaken a scientific interest in this little under- 

 stood country. 



Frank Collins Baker. 



Chicago Academy of Sciences, 

 July, 1895. 



