Dall and Harfsr/i — The PyramideUklce. 13 



Spiral marking's consistiiiii- of a slroiiir peripheral keel 

 iSubg. Scalcnostoma Dcshaycs, 18():;5. 



Type, Seitloiostamd i-mintita Desh. 



Spiral markings consisliiiiiof a peripheral sulcus 

 Subg. Jordaniella Chaster, 18!)8. 



Type, Turbo nivosa Montagu. 



Spiral sculpture absent or indicated only by extremely tine 

 microscopic lines of growth or striie; surface polished 

 Summits of the whorls with a strongly tabulated 

 shoulder 



Subg. Spiroclimax Morch, 1874. 



Type, SpirocUniax ncalaris Morch. 



Summits of the whorls not tabulated 

 Columellar fold present 



Peritreme discontinuous, aperture not ris.soid 

 Shell infiated, very large 



Subg. Amaura Moller, 1842. 



Tyix!, Amaura Candida Moller. 



Shell not inflated 



Subg. Odostomia Fleming, 1817. 



Shell of medium size 

 Sect. Odostomia Fleming, s. s. 

 Type, Tnrho pUcata Mont. 



Shell rather large 

 Sect. Stomega nom. nov. 



Type, Odostomia contiincua Aid. 



Shell small 

 Sect, Brachystomia Monterosato, 



1884. 

 Type, Odostomia rissoidea Hani. 



Peritreme continuou.s, aperture rissoid 

 Heida subg. nov. 

 Type, tSyrnola caloosaensis Dall. 



Columellar fold obsolete 

 Shell umbilicated 



Subg. Myxa Hedley, 190:?. 



Type, Myxa exesa Hedley. 



Shell not vimbilicated 



Peritreme continuous, aperture rissoid 

 Subg. Pseudorissoina Tate and May, 



1900. 

 Type, Stilifer tasmanica Ten-Wood. 



