154 C O N C H O L O G Y. 



SECTION VIII. 



IVISION I, Univalves, part 2. 



concamer^-t^d or chambered Uni- 

 valves, that have many regular and near 

 equidiftant cells or chambers, and a pipe 

 or ilphunculus, that opens into, and com- 

 municates from chamber to chamber. 



This chambered ftruflure, I fix as the 

 eiTential and fpecific charafter of the Shells 

 of this fecond part of the firft divifion; for 

 there occur among them not only revolved 

 and turbinated Shells, but even quite fimple 

 or no-wife turbinated ones. 



This fecond part contains fix genera, 

 one genus whereof, viz. the Orthoceratites, 

 is of a fimple figure ; four genera, as the 



LItuita?, or Croziers, Poly thalami. Turbines 

 Ammonia and Ammonoides, are all turbi- 

 nated; and the other genus, or Nautilus, 



is revolved. 



