672 PROCEEDINGS OF THE ACADEMY OF [1900. 



ADDITIONS TO THE JAPANESE LAND SNAIL FAUNA. III. 

 BY HENRY A. PILSBRY. 



The Japanese fauna is proving very prolific in Clausilias, and 

 may yet rival the richer portions of Eastern Europe in degree of 

 specific differentiation. It is obvious that until much more merely 

 descriptive work is done, no sound generalization upon the Japanese 

 species is possible. I have therefore been satisfied to add to the 

 accumulation of facts which can tell their story only when collec- 

 tions from many more localities come to our hands. Many of 

 the species of Clausilia seem to be of restricted geographic distribu- 

 tion. Thus, the fauna of southern Hondo, Shikoku and Awaji 

 seems to have but few Clausilise in common with the Nikko region. 



The fruitful researches of Mr. Y. Hirase now enable me to add 

 several species to the fauna of Shikoku Island, and a remarkable 

 Euphcedusa to the Hokkaido fauna, the first Clausilia known from 

 that island. Moreover, he has discovered a very remarkable modifi- 

 cation of the Euphsedusan type, C. mikado, in the region of Lake 

 Biwa. 



In a former paper I described two species, C. Hirasei and C. 

 hyperoptyx, remarkable among Asiatic Clausilise for their compli- 

 cated internal armature. It is now proposed to erect a section for 

 the reception of these species. 



Section ZAPTYX nov. 



Clausilium tongue-shaped, about twice as long as wide, with 

 subparallel lateral margins, the apex much thickened on the 

 columellar side ; posteriorly emarginate or auriculate on both sides 

 of the filament or on the columellar side only; straight distally, 

 but abruptly and strongly curved near the filament. 



Shell small, the superior lamella widely separated from the 

 spiral lamella; a fulcrum and parallel lamella developed; sutural 



