﻿PROCEEDINGS OF THE UNITED STATES NATIONAL MUSEUM 



issued {^»5I\>S 0?MS h ^he 



SMITHSONIAN INSTITUTION 

 U. S. NATIONAL MUSEUM 



Vol. 102 Washington: 1952 No. 3292 



A STUDY OF AN INTERMEDIATE SNAIL HOST (THIARA 

 GRANIFERA) OF THE ORIENTAL LUNG FLUKE (PARA- 

 GONIMUS) 



By R. Tucker Abbott 



In recent years there has been increasing interest in the Thiaridae, 

 or "melaniid" snails, not only among students of mollusks but also 

 among parasitologists, for numerous species in this family serve 

 as the intermediate hosts of human trematode diseases. A few years 

 ago Thiara granifera (Lamarck), an important intermediate snail 

 host of the Oriental lung fluke {Paragonimus westermuni Kerbert), 

 was accidentally introduced and has established itself in Lithia 

 Spring, Fla. As an aid to public-health workers and parasitologists, 

 the anatomy, the bionomics, the manner of introduction, and the de- 

 tails of identifying characters of this species are given in this paper. 

 There was also a need for a study of the gross morphological features 

 of and ecological variations in Thiai^a^ before an attempt could be 

 made to solve the problems of speciation and systematic relationships 

 of the genus. 



This study was begun on Guam Island, the Marianas, and the Philip- 

 pine Islands, where field observations and collecting were carried on 

 from ]\Iay 1945 to January 1946. Further field study was undertaken 

 under the auspices of the Smithsonian Institution in January and 

 February of 1948 at Lithia Spring, Hillsborough County, Fla., where 

 bionomic studies were made on several introduced colonies of this 

 species. Most of the anatomical work was done in the division of 

 mollusks. United States National Museum, where these collections are 

 now housed. Paraffin embedding and sectioning of animals was done 

 in the Department of Zoology at George Washington University. 



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