118 EXPEDITION OF THE "ALBATROSS," 1899-1900, 



An extensive collection and a careful study of the PartuliB of Tahiti has 

 been made by A. J. Garrett, Journ. Acad. Nat. Sci. Philadelphia, Ser. 2, 

 1884-95, pp. 43-81, Pis. II. and III. Garrett spent many years upon the 

 Island, and his accounts of the distribution and relationships of the various 

 forms is thus more accurate than are those of other authors who have not 

 visited Tahiti. From hiin we learn that Partula hyalina (Figs. 1 and 2), 

 although rare, is found everywhere in Tahiti, and it also inhabits the 

 Austral Islands, and Mangaia, one of the Cook group. It nowhere gives 

 rise to any varieties, and is the most widely distributed Partula known. 

 Also, according to Garrett, Partula otaheitana (Figs. 3-8) has its head- 

 quarters in Fautaua ("Fautana") valley near Papeete, but is also found 

 " all around the Island." I failed to discover it either in Maruapoo or 

 Vaihiria valleys, and if it exists now in either of them it must be very 

 rare. Partula filosa (Figs. 9, 10) is found only in Pirse (Pirai valley), 

 wdiile Partula sinistrorsa (Figs. 11-13) is found only on the south coast of 

 " Tahiti, where it exists in profusion in the lowland forests for a distance 

 of about ten miles." It is probable, however, that Garrett has confused 

 .some of the varieties of P. sinistrorsa with P. otaheitana. Garrett found 

 the dextral P. nodosa restricted to a limited ;irea about two miles up 

 Punaauia valley on the west coast of Tahiti. I discovered a similarly 

 colored sinistral snail in Maruapoo valley immediately south of, and ad- 

 jacent to, Punaauia valley, and have no doubt that it is merely a sinistral, 

 local, variety of P. nodosa (see Figs. 14, 15). Systematic descriptions of the 

 Partulae of Tahiti have been given by Pfeiffer, Pease, Reeve, Carpenter, 

 and others. A complete citation of their works is given by W. D. Hartman: 

 A catalogue of the genus Partula, West Chester, Pennsylvania, 1881, and 

 also in I'roc. Acad. Nat. Sci. Philadelphia, 1885, pp. 203-223. 



The general topography and the names of the valleys in the neighbor- 

 hood of Papeete is given in the British Admiralty Chart of the South Pacific, 

 No. 1158, published July 22, 1895. A good general map of the Tahitian 

 streams and valleys is given in •• Kai'te der luscl Tahiti," J. A. Ilecht, 1875. 



As is well known the Island of Tahiti is ligure 8-shaped, each half of the 

 8 being formed of a separate volcanic centre. The Island has been subjected 

 to much erosion, and more than 140 deep trough-like valleys extend down- 



