Closed Sinployea Snail (Sinployea clista)
This species was described in the year 1983.
The ‘species’ occurs on the islands of Tutuila and ‘Upolu, the respective populations, however, differ from each other, and with certainty represent at least distinct subspecies, or possibly even species.
The shells reach sizes of about 0,21 to 0,29 cm in diameter. 
The population of the island of ‘Upolu was not found again during field searches in the years from 1992 to 1994, and is now most probably wiped out. 
 Alan Solem: Endodontoid land snails from Pacific Islands (Mollusca: Pulmonata: Sigmurethra). Part II, Families Punctidae and Charopidae, Zoogeography. Field Museum of Natural History Chicago, Illinois 1983
 Robert H. Cowie; A. C. Robinson: The decline of native Pacific island faunas: changes in status of the land snails of Samoa through the 20th century. Biological Conservation 110: 55-65. 2003