HELIX. 19 



Subsection POECTLOZONITES, Sandberger, 1884. 



Narrowly umbilicated, conoidally lenticular, with acutely 

 angulated periphery; aperture subtrapezoidal, lip simple, thick- 

 ened within, columella short, vertical. H. BERMUDENSIS, Pfr. 



Bermuda. ' 



Section MICROPHYSA, Albers, 1860. 



Shell umbilicated, turbinately or globosely depressed, thin, 

 striulate, scarcely shining, usually light yellowish ; whorls 4-5, 

 slightly convex, slowly increasing ; aperture rounded-lunate, 

 peristome thin, the margins converging. H. BOOTHIANA, Pfr. 

 West Indies. 



Subsection PELTA, Albers, 1860. 



Shell imperforate, depressed, lenticular, thin, with concentric 

 lines, acutely carinate; whorls 5, slightly convex, the last with 

 convex base, impressed in the middle ; aperture subrhombic, 

 peristome simple, acute. H. SPIRULATA, Pfr. Central America. 



Section PELLA, Albers, 1860. 



Shell imperforate or perforate, depressed orbicular, thin, 

 striate, or plicate-striate ; whorls 5, slightly convex; aperture 

 Innately rounded, peristome simple, acute; columellar lip sub- 

 vertical, dilated above. H. BISCULPTA, Benson. South Africa. 



Phasis, Albers, 1850, proposed for a single Cape species, may 



be added. 



Group III. PATULA, Held, 1837. 



Section Discus, Fitzinger, 1833. 



H. ROTUNDATA, Muller. PI. 3, figs. 72-76. 



Perspectively umbilicated, depressed, yellowish corneous, 

 maculated with chestnut, lightly costulate-striate, spire convex ; 

 whorls 67?, planulate, the last obtusely subangulate on the 

 periphery. Diam. 8 mill. 



Middle and Northern Europe. 



H. radiata, Da Costa, is a synonym. 



Tar. TURTONI, Fleming. 



Spire much depressed, upper surface plane. 

 Var. ALBINA, Fer. Figs. 75, 76. 



Shell whitish or greenish white, without rays. An albino. 



