ZONITES. 171 



II. PERDITA, Desh. PI. 53, figs. 15-17. 



Umbilicus moderate, shell subdiscoiclal, shining, light yellow- 

 ish, hyaline ; whorls 4, narrow, slowly increasing, a little flattened 



on the base. Diam. 3 mill. 



Near Pekin, and Eastern Mongolia. 



II. DOENITZII, Reinh. PL 53, figs. 18-20. 



Narrowly perforate, thin, polished, very lightly strinlate, 

 amber-colored, whitish below ; whorls 5|, slightly convex, regu- 

 larly increasing, suture white-margined. Diam. 7 mill. 



Japan. 

 II. RADIATELLA, Reiiihardt. PI. 53, figs. 21-23. 



Narrowly perspectively umbilicated, fulvous corneous, shining, 

 radiately striate ; whorls 3J, rapidly increasing, the last double 

 the width of the penultimate, suture narrowly margined. 



Diam. 3 mill. 



Japan. 

 II. YESSOENSIS, Reinh. PI. 53, figs. 24-26. 



Perspectively umbilicated, corneous, somewhat shining, irreg- 

 ularly striated ; whorls 4^-5, a little convex, with deep suture, 

 periphery subangulated, base more convex. Diam. G'75 mill. 



Japan. 



Unfiyured Species. 



II. SINULABRIS, Martens. Siam. 



IT. MITIS, Pfr. Lao Mts., Cambodia. 



II. ARCTISPIRA and H. OBTUSA, Westerlund. Japan. 



[Section ZONITOIDES, Lehmann, 18G4. 

 II. NITIDA, Miiller. PL 53, figs. 27, 28, 29-32. 



Moderately umbilicated, thin, shining, yellowish corneous, 

 delicately striate, pellucid; whorls 5, a little convex, rather 

 slowly increasing, periphery compressed and almost obtusety 

 angulated, base excavated around the umbilicus. 



Diam. 7'5 mill. 



Europe ; United Sfates, Japan and Australia (introduced). 



The S3nionyms are H. hydrophila, Ingalls (for American spe- 

 cimens); H. tenuis, Dillw.? //. succinea, Stud.; //. nitescenSj And/. 



