SMITHSONIAN EXPLORATIONS, I928 



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story. Thev are true Calciphils. that is. lovers of limestone, and are 

 restricted and dependent upon exposed limestone surfaces. They are 

 absolutely unable to exist in the meadows or grasslands, and yet we 

 find them in every suital)le habitat of all the Tertiary mogotes scattered 

 throughout the range mentioned above. Their distribution must date 

 back to the days following the Oligocene uplift when they were able 

 to travel over an unbroken surface throughout their present range. 

 Since then the tooth of time has been busily engaged in returning to 

 the sea her treasures, and wherever you look, you see the process in 

 action. There are still extensive areas of rugged blocks with bold 

 escarpments in places, while in others the paredones have l)een reduced 

 to the size of a door, but by far the greater area has yielded completely 

 to the force of erosion. 



Wherever there is still a bit of limestone showing, there one may 

 find CJioiidropoiiia sagcbiciii and its associates, usually sufficiently 

 modified by their long isolation and inbreeding to present certain fixed 

 characters that will enal)le the careful student to recognize these 

 isolated colonials, even when removed from their home. To the 

 student of genetics. Western Cul)a presents a wonderful and gigantic 

 laboratory in which nature has l)een conducting her experiments in 

 heredity on a lavish scale. 



Havana Province for the greater part is low and under cultivation, 

 l)ut the Jaruco Mountain complex in the northeastern portion of the 

 province, Sitio Bonilla and Sitio Perdido, present a veritable labyrinth 

 of limestone blocks and strings of blocks and paredones. Here we 

 found the dififerentiation of Urocoptids simply marvelous, the shells 

 varying from short to long, thick to thin, and smooth to ribbed and 

 hollow ribbed, and it will be years before the last sul)species will have 

 been made known from this region. 



In Matanzas Province we made the city of Matanzas our head- 

 quarters. We covered the northern part by automobile, penetrating as 

 far east as Cardenas and southeast to Banos de los San Miguel. Two 

 things are outstanding in our memory — the visits to Fundador and 

 to the Yumeri X'alley. Fundador may be called the '' Cradle of Cuban 

 Malacology," for it was here that Dr. Louis Pfeiffer, Dr. Juan Gund- 

 lacli and Dr. Otto, three enthusiastic young German naturalists, came 

 in 1839. Pfeifl:'er with the intention of making an exhaustive study of 

 the Cuban mollusks in three months ; Gundlach to get acclimated be- 

 fore going to Surinam ; and Otto, looking for medicinal plants. 



These men collected a large amount of material about b^mdador and 

 the adjacent region which was described by Pfeiffer. Gundlach fell 



