VI PREFACE. 



It will be curious to learn the distribution of the land shells on the 

 different islands. Mr. John H. Redtield, you, and myself must make a 

 special expedition to Bermuda, have a skiff, and visit them all." 



At the end of December the Professor was attacked by a fever then 

 prevalent, and died on the 19th of January, 1853. A tablet in the 

 graveyard at St. Thomas, recording that it was " erected by his friends, 

 resident in the United States, who appreciated his worth, and sympa- 

 thized with him in his pursuits," marks the spot where his remains 

 repose. 



After the death of Professor Adams, Mr. John 11. Redfield and 

 myself, at the request of his widow, Mrs. Mary H. Adams, took charge 

 of his duplicate shells, and I contimied much of his correspondence. 



Enjoying such, and other great advantages, especially the active 

 co-operation of my esteemed friend Mr. John II. Redfield, I pursued the 

 study of the West India land shells. 



It would be difficult to enumerate the names of all to whom I liave 

 been indebted for information and specimens, but I have mentioned 

 many in the Notes appended to the annexed Catalogue. To all I offer 

 my gi'ateful acknowledgments, paiticularly to my worthy friend Mr. 

 Hugh Cuming, of London, for his unvarying kindness and liberality. 



I should also express my great obligations to Professor Poey and Dr. 

 Gundlach of Havanna; to them Naturalists generally owe very much of 

 their knowledge of the fauna of Cuba. From an intimate correspon- 

 dence with the former (carried on since 1852), 1 personally have 

 derived much instruction and encouragement. 



The invaluable Monographs, and other works of Dr. Pfeiffer, have 

 afforded assistance, the importance of which cannot be over-estimated. 



The subject of Zoological Geography has latterly met with increased, 

 and 1 may add, since the appearance of Mr. Darwin's remarkable work 

 on the Origin of Species, increasing attention. 



The facts as to the distribution of land shells compared with that of 

 other organized beings, are peculiar, and this appears to be an appro- 

 priate time for the publication of such data and information as I have 

 collected on the questions involved. 



Accordingly, and in performance of the obligation which I assumed 

 on the decease of Professor Adams, I have prepared the subjoined paper. 



By a strange and sad coincidence I received, a few months ago, much 

 assistance in the compilation of the Catalogue and Tables from the Pro- 

 fessor's son, my young friend, Charles B. iVdaras, whose recent untimely 

 death I sincerely lament. 



T. Bland. 



BrooklYxV, N. y., October, 1861. 



