NATTCA. 33 



and others the name of N. didyma^ Bolten (fig. 81), an author 

 scarcel}' qiiotable ; N. vesicalis, Phil. (fig. 92), has also been 

 used in this connection; but N. ampla has priority of position, 

 although published at the same time as N. vesicalis. Other 

 synon^^ms are : N. robusta, Dkr., N. Lamarckiana (fig. 8G), N. 

 Ghemnitzii (fig. 82), N. Petiveriana (fig. 91), and N. intermedia 

 of Recluz ; N. problematical Reeve (fig. 93) ; iV. i^^Pl/t^f^c^O'i 

 Busch (fig. 85) ; K. bicolor, Schrenck, not Phil. ; iV^ incisa, Dkr., 

 and perhaps N. glaucina, Lam., not Linn. 



X. BicoLOR, Phil. PL 11, fig. 94. 



Depressed orbicular, smooth, yellowish brown above, whitish 

 beneath ; umbilicus spirally striate, and few ridged, callus small, 

 bipartite, chocolate-color ; aperture dark chocolate above, whitish 

 infei'iorl}'. Length, 28 mill. 



Chinese Sea, Japan. 



Perhaps only a variet}' of the preceding species. 



K Incei, Phil. PI. 10, figs. 87-90 ; PI. 11, fig. 95. 



Yellowish-, brownish-, or livid-white, chocolate, etc. ; depressed 

 orbicular ; umbilicus entirely filled with a button-like callus, the 

 rounded margin of which is sometimes deeph^ grooved ; aperture 

 white, or tinged with chocolate. Length, 1-1*25 inches. 



Southern Coast of Australia. 



The sj-nonj'ms are N. Baconi (fig. 95), and N. fibula (fig. 89) 

 of Reeve, and N. clavata, Sowb. (fig. 90). 



N. Josephine, Risso. PI. 10, fig. 84 ; PI. 11, fig. 9G. 



Depressed globose, widely umbilicated, but the umbilicus 

 mostly filled by the flattened callus ; glaucous or yellowish brown 

 above, usually lighter or whitish beneath, aperture chocolate- 

 colored, white inferior!}'. Length, 1 inch. 



Southern Europe. 



It is N. glaucina of Reeve and other authors (fig. 96), not of 

 Linnseus or Lamarck ; N. olla, Desh. ; N. Philippiana, Recluz 

 (fig. 84) ; N. albumen, Scacchi, etc. 



X. DUPLiCATA, Say. PI. 12, figs. 3-5 ; PI. 13, fig. 10. 



More or less conicall}- globose, obsolete!}^ spirall}- engraved, 

 and obliquely longitudinally striated, often with a slightly 



