HISPANIOLAN AND BAHAMAN ANNULARIIDAE 171 



INCERTIPOMA 



Incertipoma is a designation for a heterogeneous group of annulariid 

 mollusks of which the operculum is unknown and whose other shell 

 characters do not conclusively reveal systematic relationship. 



The name is used in lieu of a generic name and is therefore to serve 

 as a catch-all for all annulariids that cannot be definitely assigned to 

 their proper genus. For these, it is a mere temporary designation from 

 which they are to be relieved when adequate information will come to 

 hand that will make it possible to place them in tlieir proper genus. 



Incertipoma is never to have a genotype designated and is intended 

 to last only as long as imperfectly known annulariid species exist. 



KEY TO THE SPECIES OF INCERTIPOMA 



Peristome simple. 



Shell of turbinid outline subglobosum 



Shell of elongate-conic outline. 



Axial ribs forming tufts at the summit ferox 



Axial ribs distinct at the summit elegantissimum 



Peristome double. 



Shell depressed-helicoid solutum 



Shell not depressed-helicoid. 



Shell of turbinid outline lamellosum 



Shell not of turbinid outline. 

 Shell elongate-ovate. 



Spiral sculpture restricted to umbilicus virile 



Spiral sculpture not restricted to umbilicus. 

 Last whorl adnate. 



Shell dark purple reeveanum 



Shell flesh colored rete 



Last whorl solute. 



Shell very thin diaphanum 



Shell not thin. 



Outer peristome reflexed difficile 



Outer peristome not reflexed goavense 



Shell not elongate-ovate. 

 Shell elongate-conic. 



Axial ribs forming tufts at the summit. 



Peristome strongly rayed marinum 



Peristome not rayed samanicolum 



Axial ribs not forming tufts at the summit 



Shell slender nesiotes 



Shell not slender sanjuanense 



Shell cylindroconic dominicense 



INCERTIPOMA SUBGIiOBOSUM, new gpecles 



Plate 29, Figure 6 

 Shell subglobose, the nuclear whorls and the first postnuclear turn 

 chestnut-brown; the rest pale yellow marked by more or less arrow- 

 shaped areas of brown, whose point is directed backward, and which are 



