TUB NAUTILUS. 123 



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

 bilamellate, lamellae long ; palatal plicae devel- 

 oped. Section Lamellovum n. sect, 

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

 sigmoid or nearly straight, sometimes calloused or 

 bearing lamellEfc, 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. 



vSection TornatelUna. 

 dd. Aperture having columellar and a parietal 

 lamella and more or less serrate, vertical, 

 palatal ribs, at least in tlie neanic stage. 



Section Lamellino 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 Elasmatlna Petit. 

 aa. Axis urabilicate or perforate throughout ; columella not 

 sinuous or truncate. Genus Touxatei-lides n. gen, 



b. Columella unarmed at all stages of growth. 



Section Tornatellides. 

 bb. Columella bilamellate, at least in the young. 



Section Tornntellaria, n, sect. 



Types of the Genera and Minor Groups. 



Frickella Pfr. 1855, type Achatinella amoena Pfi-, 



Auriculella Pfr. IS");}, type A. auricula (Fer.). 



Elasmias Pils. 1910, type Tornatelliaa aperta Pease. 



Lamellovum Pils. 1910, type TornatelUna globosa (Petit). 



TornatelUna Pfr. 1842, type TornatelUna clausaz=bilameUata (An- 

 ton). 



LamelUna Pease 1860, type Lamellina serrata Pease. 



Lamellidea Pils. 1910. type TornatelUna peponayn (GId.). 



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

 ton). 



