THK NAUTILUS. 123 



cc. Spire of 6 to 7 close whorls ; columellar callus 

 bilamellate, 'lamellae long; palatal plicae devel- 

 oped. Section Lamellovum n. sect. 

 bh. Shell oblong-conic or turrite, very thin ; columella 

 sigmoid or nearly straight, sometimes calloused or 

 bearing lamellae, not truncate or excavated at base. 



Genus TORNATELLINA Pfr. 



c. Shell oblong-conic ; whorls 5 to 7. 



d. Aperture having a columellar and a pari- 

 etal lamella and two palatal folds. 



Section Tornatellina. 

 (id. Aperture having columellar and a parietal 

 lamella and more or less serrate, vertical, 

 palatal ribs, at least in the neanic stage. 



Section Lamelliiia Pse. 

 ddd. No palatal armature at any stage ; colu- 

 mella more or less sinuous, sometimes 

 lamellate, whorls 5 to 6. 



Section Lamellidea, n. sect. 

 cc. Shell long-turrite, whorls 9 to 10. 



Section Elasmatina Petit. 

 aa. Axis umbilicate or perforate throughout ; columella not 

 sinuous or truncate. Genus Tornatei.lides n. gen. 



b. Columella unarmed at all stages of growth. 



Section Tornatellides. 

 bb. Columella bilamellate, at least in the young. 



Section ToriKitellaria, n. sect. 



Types of the Genera and Minor Groups. 



Frickella Pfr. 1855, type Achatinella amoena Pfr. 



Auriculella Pfr. 1855, type A. auricida (Fer.). 



Elasmias Pils. 1910, type Tofnatellina aperta Pease. 



Lamellovum Pils. 1910, type Tornatellina glohosa (Petit). 



Tornatellina Pfr. 1842, type Tornatellina clausa-=.bilamellata (An- 

 ton). 



Lamellina Pease 1860, type Lamellina serratn Pease. 



Lamellidea Pils. 1910. type Tornatellina peponum (Gld.). 



Elasmatina Petit 1843, type E. subulata Pet. = T. turrita (An- 

 ton). 



