PREFACE 



The present volume is chiefly concerned with the subfamily 

 Vertigwina, to be completed in the next and final volume on 

 Pupillidffi. 



In treating of these snails the author has had the advan- 

 tage of assistance from Dr. V. Sterki with the American Ver- 

 tigines. The portions relating to Hawaiian species are in 

 large part due to the collaboration of Dr. C. Montague Cooke, 

 though all of the species have been studied by both authors. 



The work is based on material contained in the following 

 collections, chiefly in the first two : 



The Academy of Natural Sciences of Philadelphia. 



The Bishop Museum, Honolulu. 



The Museum of Comparative Zoology, Cambridge. 



The United States National Museum. 



The Carnegie Museum, Pittsburgh (Sterki collection). 



The Indian Museum, Calcutta. 



The Bryant Walker collection, Detroit. 



In addition to the naturalists mentioned in Vol. XXIV, 

 page vi, the author desires to express his thanks for mate- 

 rial to 



Dr. S. Stillman Berry of Redlands, California ; 



Mr. William H. Clapp, Cambridge, Massachusetts; 



Major M. Connolly, London. 



H. A. P. 



PHILADELPHIA, NOVEMBER, 1919. 



(v) 





