THE NAUTILUS. 79 



very slightly descending anteriorly, very slightly angular in front, 

 becoming rounded. Aperture lunate, moderately oblique; peristome 

 thin, narrowly retiexed. Alt. 20.5, diam. 29. G, width of umbilicus 

 3 mm. 



Amagisan, Izu. Type no. 85753 A. N. S. P., from no. 1140 of 

 Mr. Hirase's collection. 



This is one of the finest of the japonica group of species, resemb- 

 ling G.jacobii in contour, but much larger, with a comparatively 

 wider umbilicus and darker in color. It is named in honor of Dr. 

 O. von Moellendorff, in whose untimely death malacology has lost 

 one of the most acute and industrious authorities upon Oriental snails. 



Pristiloma japonica n. sp. 



Shell minute, imperforate, discoidal, the upper surface very low, 

 conoidal, base convex, periphery rounded; pale yellow, somewhat 

 translucent, glossy and almost smooth, very faintly striate radially 

 above. Whorls 5^, slowly widening, slightly convex, the base im- 

 pressed in the center. Aperture nearly vertical, narrowly lunate, 

 the outer lip acute and thin, strengthened a short distance within by 

 a white, callous ridge, showing as a buff streak outside; columellar 

 margin narrowly reflexed at the insertion. Alt. 1.5, diam. 2.7 mm. 



Toya, Kuziro, in eastern Yesso. Types no. 85754 A. N. S. P., 

 from no. 1146 of Mr. Hirase's collection. 



It is impossible to say whether this is really a Pristiloma until the 

 jaw and teeth can be examined ; but from the close resemblance of 

 the shell to P. lansingi, the generic reference seems probable. There 

 is no Oriental group to which it could properly be referred, to my 

 knowledge. It is a new generic type for Japan. 



NEW PISIDIA. 



BY V. STERKI. 



Pis. complanatum n. sp. Mussel inequipartite, slightly oblique, 

 moderately inflated ; superior margin short, somewhat curved, with 

 rounded, more or less projecting angles at the scutum and scutellum ; 

 posterior part short, truncate, passing with a rounded angle in the 

 inferior margin, which rises in a strong curve to the rounded-angular 

 anterior end ; supero-anterior slope not well marked, slightly curved ; 



