EXPLANATION OF PLATE IV. 



Fiffurc 10.10. Natica imperforata, Nobis. 



N. testii ventricoso-ellipticu, solidii, imperforata, rufo-zona- 

 ta, longitudinaliter lineata ; lineis crebris, luteis undulatis; 

 callo prominenii ; labro acuto. 



Hab. ? 



I have several specimens of this beautiful shell, va- 

 rying in size from one-half to three inches, and they 

 have not the slightest trace of an umbilicus. It 

 does not therefore properly belong to the genus Na- 

 tica. The callosity is colored beautifully black on 

 the upper part, and the inferior two-thirds white. 



Figure 11.11. fiERiTia A papillosa, Nobis. 



N. testa ovata, tenui, atra ; papillis atris ; apertura albo- 

 caerulescente ; labro tenui, supernc biauriculato. 



Hae. ? 



