46 STROBILOPS, S. G. DISCOSTROBILOPS, 



does not quite attain the edge. Both penetrate one-third of a 

 whorl and have strongly nodose edges (fig. 14). About one- 

 fourth of a whorl behind the aperture there is a barrier com- 

 posed of a short acute columellar lamella, three basal folds, 

 of which the second from the axis is largest, sometimes a 

 minute fourth fold at the periphery, and there is a short fold 

 mthin the outer wall above it (fig. 11 ; in this example the 

 third basal fold is longest, an exceptional condition). All of 

 these folds are usually visible in an oblique view in the aper- 

 ture, and also by transparence through the base. 



Height 2.2, diam. 3.5 mm, ; 5 whorls. 



Japan: Yonezawa, Uzen (Y. Hirase). 



This beautiful little snail is larger than others known from 

 Asia — in fact, after the Endoplaces, the largest recent species 

 of Strobilops. It is more depressed than S. hirasei and has 

 more numerous basopalatal folds. It is closely related to the 

 Korean S. coreana, but is much larger, with a relatively wider 

 umbilicus. There is some variation in the basal folds (as in 

 fig. 11) among the ten specimens examined, but most of them 

 agree with the type. 



Subgenus Discostrobilops, n. subg. 



Gruppe der Strohilops uniplicata Wenz, Neues Jahrb. Min., 

 Geol. u. Pal., 1915, II, p. 86. 



The shell is thin, strongly depressed, the height less than 

 half the diameter, subdiscoidal with well-opened umbilicus; 

 finely eostulate or rib-striate above, smoother beneath. Pari- 

 etal lamella emerging; infraparietal lamella either wholly im- 

 mersed or weak and emerging; deep within, the edges of the 

 lamella are either smoothish or sparsely pi'ickly, without knots 

 or nodes; interparietal lamella either present or absent. There 

 is no columellar lamella. Basal folds three or four. Type S. 

 huhhardi. 



Distribution : warm temperate to tropical parts of North 

 America and the West Indies; Upper Oligocene and Miocene 

 of Germany and Czechoslovakia. 



This group comprises a single variable living species in 

 America and one species, S. uniplicata (Sandberger), with two 



