SANTO DOMINGO TYPE 

 SECTIONS AND FOSSILS 



STRATIGRAPHY 



Preliminary Note 



Since the publication and distribution of Bulletin of Ameri- 

 can Paleontology, No. 29, Sections 1 and 2, comprising the sys- 

 tematic discussion of our Santo Domingo fossils, quite a number 

 of Gabb's 1873 shells in the Philadelphia Academy's collection 

 have been described, without figures, as new species by Drs. 

 Pilsbry and Johnson.* No doubt a number of these are not 

 represented in our collections and should be added to the Santo 

 Domingo fauna. Some species, however, described as new by 

 Drs. Pilsbry and Johnson will prove identical with mine and will 

 pass into synonymy, since mine have priority. For, Section 

 1 (pages 1- 1 20) of Bulletin 29 was published and distributed 

 March 31, 1917 and Section 2 (pages 121-240), April 29, 1917, 

 while Drs. Pilsbry and Johnson's Adva?ice Descriptions were not 

 issued until May 4, 1917, as stated on the cover of their separ- 

 ates. 



Characteristics of the Fossil Faunas 



Our faunas, systematically discussed in Bulletin 29, forming 

 Part 1 of this memoir, show three striking features which are to 

 some degree deceptive: — (1) Many resemble the recent. (2) The 

 nearest living allies of certain species are deep sea forms. (3) The 



*New Mollusca of the Santo Domingan Oligocene. Proc. Acad. Nat. 

 Sci. Phila., designed for the April nnniber which was not issued in April. 

 Advance separates issued May 4, 1917. 



