AMPHIDROMUS SEMIFRENATUS. 



155 



which he decided were a variety of A. semifrenatus IMarts., 

 while he possessed also specimens as carinate as the smal- 

 ler one, which may possibly belong also to this species. 

 Thinking it might be of some interest to conchologists, the 

 more so while there are not existing in literature, as far 

 as I know, figures of A. semifyenatus^ I am giving here 

 figures of both specimens. 



The larger one (figs. 1 en 2), Leyden Museum Amphi- 

 dromns 51a., is collected at Tapatoean, Atjeh, northwest- 

 coast of Sumatra, and presented 

 to the Museum by Mr. H. E. 

 Wempe. The shell is greyish 

 brown, darkest on the latter half 

 of the last whorl. A small dark 

 chestnut zone surrounds the clo- 

 sed umbilicus. The last wliorl 

 and the latter half of the pen- 

 ultimate whorl are encircled by 

 a small peripheral band, com- 

 posed of alternating white and 

 chestnut blots, resembling that 

 existing in A. sumatramis. The 

 former half of the penultimate 

 whorl and the preceding one are 

 wholly covered with irregular 

 alternating, larger white and 

 narrower chestnut stripes; in 

 the middle is to be seen very 

 indistinctly a small band in the groundcolour of the shell. 



The apex is blackish; the first whorls are corneous. 



The smaller specimen (fig. 3), Leyden Museum Amphi- 

 dromus 57/^, is yellowish, carinate at the last whorl; its 

 apex is blackish. This specimen was collected at Poeloe 

 Weh, a small island northwest of Sumatra, by Dr. P. 

 Buitendijk, who enriched the collections of the Leyden 

 Museum already with many valuable specimens from nearly 

 all classes of animals. 



Leyden Museum, March 1, 1913. 



Notes from tlie Leyden ]Museuiii, Vol. XXXV. 



Fi-. 2. 



