HELIX-DENTELLARIA. 81 



A well-characterized section, allied to Lucerna and Cepolis. The 

 species are well-defined and easy to recognize ; and transition forms 

 are rare. A number of South American species belonging to 

 Isomeria have been referred here erroneously by several recent au- 

 thors. The species all inhabit the Caribbean islands. Swainson's 

 subgenus Cyclodoma (Malacol. p. 193) does not belong in the synon- 

 ymy of Dentellaria, where Pfeiffer places it, but probably equals in 

 part Ochthephila and Polygyra. 



Key to the species of Dentellaria. 



Teeth of basal Up tubercular, not compressed nor entering, position 

 of tooth not marked behind the peristome by a pit or groove ; peristome 

 sometimes without teeth. 



Parietal wall toothed, 



Outer lip bidentate ; basal lip denticulate, nuxdenticulata. 



Outer lip not dentate, 



Basal lip with one or two teeth, 



Parietal tooth long, triangular, nucleola. 



Parietal tooth short, tubercular, obesa. 



Basal lip without teeth, paritis. 



Parietal wall not toothed, 



Parietal callus microscopically granulate, 



Shell large, peristome toothless, orbicidata. 



Shell smaller, basal lip toothed, dentiens. 



Parietal callus smooth, Isabella. 





 Basal lip with a compressed entering tooth near its junction with the 



outer lip, marked behind the peristome by a groove or scrobiculation. 



Surface granulate, whorl deflexed at aperture, 

 Granulation minute, 



Color light, with dark bands, josephinw. 



Color dark, bands obscure or wanting, 



Acutely carinated, large, lychnuchus 



Obtusely carinated, small, badia. 



Granulation coarse, 



Acutely angulated, perplexa. 



Periphery rounded, formosa. 



Surface smooth, not granulate, whorl not deflexed, 



No parietal tooth, pachygastra. 



A strong parietal tooth, nigrescens. 



Surface hispid ; umbilicus not covered, auridens. 



6 HELICID^E. 



