SMITHSONIAN EXPLORATIONS, I927 59 



rapidly coming back. A series of undersea photographs taken in dif- 

 ferent years in the same place show the changes which occur in the 

 region from year to year, and over a number of years, produces a 

 very interesting record as to what really takes place. Not only that, 

 but with the aid of the undersea camera, it has been possible to 

 show the associations of different types of animals in the different 

 regions. These faunal associations are exceedingly definite and in- 

 teresting not only to the student of living organisms but also to the 

 student of fossil creatures, for you may have the reef building corals 

 in one place with all the fish, mollusks, echinoderms, gorgonians, 

 worms, etc., associated therewith, and not more than 50 feet away 

 vou may have a grass flat with an entirely different assemblage of 

 creatures always found there and peculiar to such a place. If you 

 were to have these creatures fossilized, and you had two exposures, 

 one yielding the grass flat fauna and the other the reef fauna, you 

 might be hard put to understand that these things were really syn- 

 chronous elements. In order to have a definite record of the changes 

 and also faunal associations, I have taken undersea pictures of these 

 things, as tiine permitted, and likewise a series of undersea moving 

 pictures, which show the animals in action. During 1927 I added 

 2,900 feet of moving picture film and 144 O Graphic films. 



WEST INDIAN LAND SHELL STUDIES 



The late Mr. John B. Henderson, formerly a meml)er of the Smith- 

 sonian Board of Regents, had intended to devote the major portion 

 of his scientific eft'orts to a study of the West Indian land shell prob- 

 lem. With that end in view, a numl^er of expeditions were made by 

 him and the writer, and various other friends, |)articularly Dr. Carlos 

 de la Torre, of Havana, to many ]:>laces in the Greater Antilles. These 

 expeditions, as well as old collections purchased by Mr. Henderson 

 and the material secured from collectors more recently has given 

 to the U. S. National Museum jM-obably a larger series of West 

 Indian material than is contained in all the other museums of the 

 world together. Thanks to financial aid rendered Ijy Dr. Charles T. 

 Simpson, of Little River, Florida, it has been possible to obtain 

 necessary assistance to push this work on the West Indian land 

 shell problem more rapidly than would otherwise have been possible, 

 and this has resulted in the ])ractical completion of a monograph on 

 the large family of land shells known as the Annulariidae. 



In order to make this monograph as comi)lete as possible, the 

 writer in September visited Dr. Carlos de la Torre at Havana, Cuba, 

 to examine his rich private collection, which embraces by far the 

 most magnificent assemblage of Cuban land mollusks in existence. 



