DUTCH BOUNEO-EXPEDITION. 153 



is divided ia a short flagellura of S'/g mill., with a thin 

 muscle which was united with the prostata ; the bent part 

 of the penis is nearly 5 mill. ; on its top a long, slender 

 retractor and the vas deferens, leading to the prostata, 

 are inserted. 



12. Ryssota Broohei Adams & Reeve. 



Adams & Reeve, Zool. Voy. Samarang, Moll. p. 60; 

 pi. 15, figs. 4a, 46. — Reeve, Conch. Icon. fig. 377. 



Localities: Mouth of the Mandai River, May 1894 (Büt- 

 tikofer). — Foot of Mount Kenepai (Büttikofer). 



From the first named locality a rather young specimen , 

 with the oblique folds of the superior side of the shell 

 well developed. The other specimen is full-grown with a 

 thickened peristome. 



13. Dyakia nasuta Metcalfe. 



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

 Reeve, Conch. Icon. fig. 1031. 



Locality: Top of Mount Klam near Sintang, January 

 1894 (Hallier). 



A few specimens , the largest of which measures only 

 24 mill, instead of 35, as is mentioned by the author; 

 having also a whorl less, it may be a young one, though 

 the projection of the aperture is already faintly marked. 

 The specimens are too little in number, to describe a 

 new variety upon , which will probably prove to be desirable 

 when more material is at hand. 



14. Dyakia Lindstedti Pfr. var. castaiua E. A. Smith. 



Smith, Proc. Zool. Soc. London, 1895, p. 103. 

 Localities: Foot of Mount Semedoem , 350 M., and foot 

 of Mount Daraoes (Hallier). — Sintang (Goedhuis). 



15. Dyakia mindaiensis Bock. 



Bock, Proc. Zool. Soc. London, 1881, p. 633; pi. 55, 

 fig. 7. 



Notes from the Leyden Museum, Vol. XVII. 



