NOMENCLATURE. 17 



papillaris. Papillary : opposed to acute, having 

 the apex semi-globular. 



Articuli. Joints ; the parts of the whorls, in 

 some of the Nautili, between the genicula. 



Basis. Base ; the opposite extremity to the 

 apex ; in some shells that part of the belly 

 which is next the aperture, in others the 

 very lowest point of the beak. In this 

 sense it is either emarginate, indented by 

 a deep canal, or entire, without indenta- 

 tion. 



Canalis. Canal; a continuation or prolonga- 

 tion of the aperture along the beak, which 

 forms a gutter by the involution of its sides. 



Cauda, Rostrum. Beak ; the elongated bases 

 of the belly, lips, and columella. 



abbreviata. Abbreviated ; shorter than the lower 

 whorl. 



clausa. Closed ; having the edges of the canal 

 meeting, or nearly so. 



elongata. Elongated ; longer than the body. 



explanata. Plain : dilated at the margins. 



truncata. Truncate; cut off transversely. 



