PUPILLA. 153 



Classification. The Pupillas divide into four sections (the 

 first three new), characterized thus: 



a. Embryonic shell rather coarsely reticulate-grauose ; the 

 rest regularly rib-striate. 



Section Striopupilla, type P. sterkiana. 



a 1 . Embryonic sculpture minute; striation elsewhere faint or 

 weak. 



b. Whorls increasing rather rapidly in height; spire 



convexly tapering from the last whorl, which is 



widest. Section Afripupilla, type P. tetrodus. 



b 1 . Whorls increasing slowly; shell cylindric with, short, 



convexly-conic summit. 



c. Aperture having 2 to 5 teeth, an angular 

 tubercle often present; apical whorls pitted- 

 reticulate. 



Section Primipupilla, type P. signata. 

 c 1 . Aperture having to 3, rarely 4 teeth, no an- 

 gular tubercle ; apical whorls most minutely 

 granulose. 



Section Pupilla proper, type P. muscorum. 



The geographic relations of these sectional groups may be 

 represented thus: 



Europe Asia, America 



Pupilla Pupilla Pupilla 



Primipupilla Primipupilla Striopupilla 



Primipupilla Primipupilla 

 Afripupilla 



Africa Australia 



The species are described under geographic groups : 



I. North America: species 1 to 6. 

 II. Europe, North Africa: species 7 to 15, 21. 



III. Asia : species 7, 13, 16 to 20, 22 to 29. 



IV. Africa, Cape Verde Islands, Reunion I. : species 30 



to 32. 



