78 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 58, 



EUTUDORA, new genus. 



Shell ranging in form from turbinate to elongate-conic. The 

 axial sculpture may consist of sublamellar riblets, or may be almost 

 reduced to lines of g^rowth. The spiral sculpture may be strong or 

 feeble. A breathing notch, sHt, pore or siphon is present. Oper- 

 culum typically Tudoroid. 



Type of the genus. — Cyclostoma limlifera (Menke) Pfeiffer. 



EUTUDORISCA, new subgenus. 



Shell almost turbinate in form, spiral cords much stronger than 

 the axial sculpture, which is decidedly reduced, almost obsolete. 

 A notch in the parietal callus near its junction with the outer lip 

 leaves a breathing space here, when the animal is withdrawn. Oper- 

 culum typically Tudoroid. 



Type of the subgenus. — Cistula jimenoi (Arango) Pfeiffer. 



The following species are now referred to this subgenus: 



Cistula jiinenoi (Arango) Pfeiffer Havana. 



Cyclostoma catenata Gould Havana. 



EUTUDORELLA, new subgenus. 



Shell almost turbinate in form. Spiral cords much stronger than 

 the axial sculpture, which is almost obsolete. A slit in the parietal 

 wall connects the breathing pore with the outer face of the peristome. 

 Operculum typically Tudoroid. 



Type of the subgenus. — Cistula agassizii (Charpentier) Pfeiffer. 



The type species is the only one known of this group at present. 

 It comes from Havana, Cuba. 



EUTUDORA, new subgenus. 



Shell almost turbinate. Spiral cords much stronger than the axial 

 sculpture, which is almost obsolete. A breathing pore is present in 

 the parietal wall a little anterior to the junction with the outer lip. 

 Operculum typically Tudoroid. 



Type of the subgenus. — Cyclostoma limbifera (Menke) Pfeiffer. 



The type species is the only one known of this group at present. 

 It comes from Havana, Cuba. 



EUTUDOROPS, new subgenus. 



Shell ranging from ovate-conic to elongate-conic. Axial sculpture 

 consisting of slender sublamellar riblets, which are rendered wa,vy by 

 the low-rounded spiral cords. Breathing pore with or without 

 external siphon. Operculum typically Tudoroid. 



Type of the subgenus. — Cyclostoma torquaturn (Gutierez) Poey. 



