296 1>YRAMIDELLID^. 



mella with several plications, lip thickened, often expanded. P. 

 AURis-CATi, Chemn. 



This is the restricted P3'ramidella of H. and A. Adams and 

 most of their successors ; the smooth shells which Lamirck 

 designated by that name, being generally known as Obeliscus. 

 The erroneous application of these names has become so well- 

 established that I confess I follow Dr. Fisher with some reluc- 

 tance in his correction of the errors. 



Subgenus Syrnola, A. Adams, 18G0. 



Shell small, subulate, polished ; whorls flattened, suture well 

 marked ; columella with a single plication, outer lip simple. 



The Syrnolas are small, slender P^-ramidellids, with a single 

 columellar plait. P. gracillina, A. Ad. 



Section Agatha, A. Ad., 1860. 



Shell oval acuminated ; spiral plication very strong. P. aus- 

 TRALis, Angas. 



Section Amathis, A. Adams, 1861. 



Aperture dilated, rounded in front, acute behind. Possibly 

 synonymous with Agatha. P. vjrgo, A. Ad. 



Section Oscilla, A. Adams, 186T. 



Shell solid, ovate or pyramidally turreted, imperforate; whorls 

 strongly spirally lirate ; aperture oval or subquadrate, with a 

 strong, transverse, median parietal plication. P. annulata, A. 

 Ad. 



Section Orina, A. Adams, 1870. 



Shell conoidal, profoundly umbilicated ; whorls flattened, 

 smooth ; aperture subquadrangular, with a single columellar fold. 

 0. PINGUICULA, A. Ad. 



Section Elusa, A. Adams, 1861. 



Shell subulate, turreted ; whorls longitudinally plicate ; aper- 

 ture ovate, columella with a single plait, outer lip lirate within. 



P. SUBULATA, P. TERES, A. Ad. 



The above groups are all founded on Japanese species, mostly 

 unfigured ; the characters appear to be unimportant. 



