OP CONCHOLOGY 299 



3. MacroceramUS. Turrited or conical, apex attenuated, last 



■whorl angulated around its base ; aperture oval, peristome 

 not continuous nor reflected, except over the columella. 

 Generally white with stripes or spots of darker markings. 



4. Pupa, Draparnaud. Cylindrical, minutely perforate, size 



very small, aperture small, lip expanded or reflected, gene- 

 rally toothed within. Animal with superior and inferior 

 tentacles. 



5. Strophia, Albers. Shell large, with obtuse apex, the whorls 



generally covered with transverse ribs. Lip thickened and 

 reflected, its extremities connected by a thick callus ; colu- 

 mella dentate. 



West Indian. 



6. Vertigo, MUller. Minute, cylindrical apex acuminate, 



obtuse ; lip expanded, white. Animal without inferior 

 tentacles. 



7. ZooGENiTES, Morse. Minute, turrited, conical, acutely 



ribbed longitudinally. Ovoviviparous. 



CIONELLA. 



Subgenera. 



ZUA, Leach. Ovate-oblong, imperforate, smooth, pellucid, 

 golden, shining ; aperture small ; lip obtuse, its extremities 

 joined by a callus ; columella more or less truncate. 



AcicuLA, Leach. Elongate, imperforate, white, vitreous, spire 

 turrited, apex slightly obtuse ; aperture oblong, lip simple, 

 acute ; columella subarcuate, truncate at base. 



ZUA, Leach. 

 1. Zua subcylindrica, Chemnitz. 



Plate 14, figure 14. 



Shell oblong-oval, thin, polished, transparent ; whorls 6, 

 slightly convex, apex obtuse, sutures well marked ; aperture 

 oval, longitudinal, lip thickened but not reflected ; umbilicus 

 impervious. Bright amber color. 



Length 7*5, diam. 2-5 mill. 



Inhabits from New England and the Middle States to Lake of 

 the Woods and the far Western Territories. 



