302 



BELEMNITES. 



NAUTILUS BELEMNITA. Gmelin. 



Encycl. Meth. pi 465, / 1 . 

 A fossil. 



ORTHOCERA. 



NAUTILUS RAPHANUS. LinnCBUS. s 



Linn^us has classed this genus, as well as the G. Spi- 

 rula, with his G. Nautilus, indicating the alliance that 

 exists betweeen the many chambered shells, or shells 

 with septa. The Orthocera is a very minute elongat- 

 ed marine shell, channelled on the exterior, resembling 

 a slightly curved horn : the interior is divided into many 

 cells, transversely separated by septa, which are tra- 

 versed by a subcentrical syphon, sometimes projecting 

 at both extremities of the shell, and sometimes only at 

 one. They are found in the sand on the Mediterra- 

 nean shores. 



Orthocera raphanus Orthocera obliqua 



fascia acicula 



raphanistrum legumen 



