158 . IJOLLUSCA OF THE 



(Büttikofer). — Mounts Dadap and Sekedau (Moret). — 

 Mount Liang Gagang (Hallier). 



The specimens from Mount Kenepai are very large, 

 the largest having a diam, raaj. of 34 mill. The only 

 one collected by Dr. Hallier is a young specimen. 



31. Pterocyclos niahensis Godwin Austen. 



Godwin Austen , 1. c. p. 340 ; pi. 35 , figs. 3 , 3a. 



Localities: Mount Tiloeng, March 1894 (Büttikofer). — 

 Mount Liang Koeboeng, April 1894, and Siniai River, March 

 1894 (Büttikofer). — Mount Liang Gagang (Hallier). 



The number of the spiral ribs and the shape of the 

 aperture seem not to be constant; Godwin Austen (1. c.) 

 mentions a total number of 6 ribs ; in the specimens 

 collected during the Borneo-Expedition , the number varies 

 from 10 to 13; however I must confess that some of 

 them are rather obsolete , and may escape notice if the 

 epidermis is well preserved. Godwin Austen has already 

 stated that the shape of the wing of the aperture is vari- 

 able; in the specimens before me, it is not so much 

 ascending as in the cited figures , even resembling in 

 this respect the figures of P. cucullus , fig. 2 of the 

 same plate. 



82. Opisthoporus euryomphalus Pfeiffer. 



Pfeiffer, Proc. Zool. Soc. London, 1856, p. 337. 

 Locality: Mount Tiloeng, March 1894 (Büttikofer). 

 One large specimen, with the tube slightly nearer to 

 the aperture than is commonly the case. 



33. Omphalotropis carinata Lea. 



Lea, Proc. Acad. Philad. VHI, p. 111. — Issel, Mol- 

 luschi Borneensi, in: Ann. del Mus. Civ. di Stor. Nat. di 

 Genova, vol. VI, 1874, p. 447; pi. 7, figs. 8, 9. 



Locality: Pontianak (MoretJ. 



One specimen. 



P^'otes from ttie Ijeyden ]Museum, Vol. XVII. 



