BOYSIDIA. 195 



The common Yangtse valley form, as well as that from the 

 Marble Rocks, near Canton, is more broadly conic with the 

 peristome barely free from the preceding whorl, and is what 

 von Mollendorff has described as conspicua. He says: "The 

 manner of life is that of Pupa avenacea and muhlfeldti, which 

 are also like it in color. They sit chiefly gregarious on naked 

 limestone rocks, leaving them only in very dry times, and are 

 often frosted over gray with lime dust, so that they are easily 

 overlooked. ' ' 



la. B. hunana conspicua Moellendorff. PI. 33, figs. 10, 12, 13, 

 14. 



Differs from the type by the distinctly more conic, more 

 solid shell, the umbilicus more open, whorls 5% to 6 (not 6 

 to G 1 /^), more rapidly increasing, the last higher and more 

 ventricose; aperture larger for the height of the shell, but 

 with quite similar lamellae and teeth, peristome more thickly 

 labiate (Mttdff.). 



China: Tsat-sing-yen or Marble Rocks of the West River 

 above Canton, prov. Guang-dung. Also Tong-king (Mlldff.). 



The specimen figured measures, alt. 4, diam. including 

 peristome 2.5 mm., with slightly over 6 whorls. Color chest- 

 nut-brown, the lip orange-cinnamon. The angular lamella 

 reaches the lip, and is concrescent with the parietal at its 

 inner end, the junction marked by a notch. Parietal is rather 

 short, high, and its inner end curves slightly towards the 

 periphery (figs. 10, 14). The columellar lamella descends ob- 

 liquely as it enters (fig. 10). The upper palatal plica slopes 

 downward a little as it enters. The peristome is distinctly 

 thickened within. 



2. BOYSIDIA DORSATA (Ancey). 



Shell conic, obscurely corneous-fulvous, rather thin, the 

 apex obtuse. Spire conoidal, 6% rather convex whorls, the 

 last inflated, rotund, somewhat narrowed before the aperture. 

 Suture impressed. Aperture rounded-oval, thrust forward; 

 peristome reflected, the margins continuous; furnished with 

 two rather deeply-placed teeth in the right margin ; two other 



