60 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, 1t was thought desirable to gather large series of specimens 
of Cerion and associated mollusks for careful study and experimen- 
tation. 
Of Certon alone about 40,000 specimens were collected from as 
many localities as possible. This was done with the idea of intro- 
Fic. 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 cther islands, so that the effect of a change 
of environment could be studied later. 
The party 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, Liguwus, 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. 
