161 THE ELEMENTS 



Siphunculus, a cylindrical canal per- 

 forating the partitions in polythala- 

 mous shells ; for instance the Nau- 

 tilus Spirula. 



Solitary, generally applied to a single 

 tooth. 



Spatulate, rounded and broad at the 

 top, and becoming narrower like a 

 spatula or battledore. 



Species, the division of a family or 

 genus, containing such as agree 

 with it in generic characters. 



Spiny, thorny, covered with thorn-like 

 processes. 



Spire, all the whorls of univalve shells, 

 excepting the one in which the 

 aperture is situated, which is termed 

 the body. 



Spiral, twisted like a cork screw. 



Squamous, scaly. 



Squarrose, consisting of scales spread- 

 ing every way, or divided into pieces 

 standing upright and not parallel 

 with the plane. 



