The shells from Sepandjang are in Chicago Natural History Museum, no. 97808, in the Zoological Museum in Amsterdam, and in Butot; Djukung specimens are in the Zoological Museum in Amsterdam; and topotypes from Bajutan are in Chicago Natural History Museum, no. 97806, and in Butot and the Zoologisch Museum, Amsterdam, Some additional material from Kangean Island (USNM 468416, Paravicini!) was seen after the description had been written.