Number 152 August 12, 1024 OCCASIONAL PAPERS OF THE MUSEUM OF ZOOLOGY UNIVERSITY OF MICHIGAN Ann Arbor, Michigan Published by the University LAND AND FRESHWATER MOLLUSCS OF THE DUTCH LEEWARD ISLANDS By H. Burrington Baker Introduction In 1920, while on the University of Michigan-Williamson Expedition to Venezuela, a small collection of land shells was obtained from the Schaarlo, back of Willemstad, Curasao. ^ In 1922, the University of Michigan Museum of Zoology sent me back to the Dutch Leeward Islands to collect molluscs, reptiles, amphibians and ants. With the assistance of an addi-tional grant from the Zoological Laboratory of the University of Pennsylvania, for the collection of grasshopper testes as cytological material, I was able to spend the summer, from June 11th to September 17th, 1922, in a study of all five of the islands of the group. The reptiles collected have been listed already, in a paper by Dr. A. G. Ruthven.^ From June 11th to 28th, Overzijde (Otrabanda), Curasao, was the base for collecting trips. From June 29th to July 1 1923; Occ. Papers, Mus. Zool. Univ. Mich., no. 137; pp. 1-7, pi. I. 2 1923 ; Occ. Papers, Mus. Zool. Univ. Mich., no. 143.