Dall and Bartsch 77ie Pyramidellidce. 1 



The status of Agatha viryo A. Adams 1860, [Menestho, 1861, Myoma, 

 18(51, Am at his 1861], is not known to us. From the meager description 

 we are inclined to believe that it is allied to Act&opyramis Fischer. 



SYNOPSIS OF THE SUBGENERA OF TUKBONILLA. 



A 1 Shell without basal keel 

 B 1 Ya rices absent 



Spiral sculpture absent, or if present consisting of micro 

 scopic striations only 



Surface of the early post-nuclear whorls marked by 

 feeble axial ribs, later ones smooth 



Subg. Prycheulimella Sacco, 1892. 



Type, Pyramidella pyramidata Desh. 



Surface marked by strong axial ribs which terminate at 

 the periphery of the whorls, intercostal spaces ex 

 cavated between the sutures. 



Subg. C'hemnitzia Orbigny, 1839. 



Type, Melania campanettce Phil. 



Surface marked by strong axial ribs and intercostal 

 spaces which extend over the periphery to the umbili 

 cal region 



Subg. Turbonilla Risso, 1826. 



Spiral sculpture present, always stronger than microscopic 

 striations 



C 1 Axial sculpture consisting of well developed ribs 

 Spiral markings consisting of many very fine spiral 

 striations 

 Aperture subquadrate 



Subg. Strioturbonilla Sacco, 1892. 



Type, Strioturbonilla alpina Sacco. 



Aperture suboval 



Subg. Pyrgolampros Sacco, 1892. 



Type, Pyrgolampros mioperplicatulus 



Sacco. 



Spiral marking absent between the sutures, base 

 strongly spirally lirate 



Subg. Sulcoturbonilla Sacco, 1892. 



Type, TornateUa turricula Eichw. 



