6o 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 60 



the " White House," near Sharp Rock Point, required a 5-pint 

 measure to contain them. There are also other characteristics 

 besides differences in size. 



On account of the many puzzling" phenomena regarding their dis- 

 tribution, it was thought desirable to gather large series of specimens 

 of Cerion and associated mollusks for careful study and experimen- 

 tation. 



Of Cerion alone about 40,000 specimens were collected from as 

 many localities as possible. This was done with the idea of intro- 



Fig. 66. — Two races of Bahama shells (Cerion) planted by Dr. Bartsch on 

 keys between Miami and Tortugas, Florida. Photograph by National Museum. 



ducing some of them into other islands, so that the effect of a change 

 of environment could be studied later. 



The part\' returned to Nassau on May 26, and then set sail for 

 Miami, where it remained until the end of the month. During this 

 time a fine series of that most beautiful of all North American land 

 shells, Liguius, was secured, as well as a goodly number of other 

 species. A number of dredge hauls were made north of Cape Florida, 

 in shallow water, by the Anton Dohrn and a fine series of marine 

 invertebrates secured. 



On May 31 the expedition sailed south for Key West. On this 

 cruise, and during the stay at Miami, the two races of Bahama 

 Cerions were introduced at different points. 



