150 MOLLUSCA OF THE 



be discovered, and the anatomical characters can be studied, 

 they will perhaps prove to belong to a new genus. 



7. Xesta glutinosa Metcalfe. 



Metcalfe, Proc. Zool. Soc. London, 1851, p. 70. — 

 Reeve, Conch. Icon. fig. 1378. 



Locality : Mount Liang Koeboeng (Büttikofer). 



With this species I identify with some doubt a broken 

 shell , wanting part of the columellar margin and adjacent 

 part of the peristome ; it is very thin and pellucid , light 

 greenish yellow, the keel but slightly indicated ; if belonging 

 to this species , it is an albino. 



8. Xesta Thishe E. A. Smith. 



Smith, Proc. Zool. Soc. London, 1895, p. 101 ; pi. 2, fig. 4. 



Locality: Mount Liang Koeboeng (Büttikofer). 



One specimen. — This species is identified by its author, 

 together w^ith some other species, which remained doubt- 

 ful, for want of materials for comparison. 



9. Hemiplecta densa Adams & Reeve. 



Adams & Reeve , Zool, Voy. Samarang , Moll. p. 62 ; 

 pi. 16, fig. 8. — Martens, I.e. p. 230. 



Locality : Near the coast of Sambas (Hallier). 



The specimens belong to a form with a very thick shell. 



10. Hemiplecta praeculta E. A. Smith. 



Smith, Proc. Zool. Soc, Loudon, 1895, p. 101; pi. 

 2, fig. 7. 



Locality: Poelau on the Sibau River, June 1894 (Büt- 

 tikofer). 



Only one young specimen. 



11. Hemiplecta Biittikoferi , n. sp. 

 (Plate 3, fig. 1). 



Shell dextral , depressedly conoid , with a narrow umbi- 

 licus , sharply angulated at the periphery, rather thin , 



Notes from the Leyden M^useum, Vol. XVII. 



