504 PROCEEDINGS OF THE ACADEMY OF [1897. 



tal glaze. Columella somewhat concave, passing gradually into the 

 thin basal lip. 



Alt. 76, diam. 40, alt. of aperture, 36 mm. 



Alt. 74, diam. 40, alt. of aperture, 35 mm. 



" Taboo, Africa " (Robert Swift coll. in A. K S. Phila.). 



This form differs from P. Saulcydi (Joaunis) in being more elon- 

 gated and slender throughout, the last whorl not concave above, 

 aperture consequently not acuminate posteriorly as in that species ; 

 the spire more elongated and tapering, and the terminal " mamelon " 

 more pronounced. 



It is also dextral ; but as the apparent sinistrality of Joannis' 

 species may possibly (though not probably) be due to an artist's 

 failure to reverse, I do not place great stress upon this feature. 



Illustrations of this and the preceding form will appear in the 

 Manual of Conchology in due time. 



