UNIVALVES. NAUTILUS. 79 



of the Nautili; but by far the greater number are found on 

 the British, and most of the European coasts. 



NAUTILUS Sailor. 



DIVISION I. Spiral, with contiguous whirls. 

 Pompilius Great-chambered. Scrobiculatus Sunken-spire. 

 *Lacustris Lake. 



Minute or Microscopic Shells. 



Calcar Spur. Balthicus Baltic. 



*Rotatus Wheel. *Crassulus Strong. 



*Laevigatulus Smooth. *Umbilicatulus Umbilicated. 



*Depressulus Compressed. *Lobatulus Lobed. 



*Crispus Keel-edged. Rugosus Rugged. 



*Beccarii Beccaria's. Umbilicatus Oblique-jointed. 



DIVISION II. Spiral, with detached whirls. 

 Spirula Ram's-horn. 



Minute Shells. 

 Spengleri Spengler's. Unguiculatus Nail-shap'd. 



DIVISION III. Elongated and almost straight. 



Minute. 



*Semilituus Half-crozier. *Spinulosus Spinous-jointed. 



Lituus Crazier. *Sub-arcuatus Sub-arcuated. 



*Carinatulus Keeled. *Bicarinatus Bicarinated. 



*Obliquus Obliquely -striated. Fascia Banded. 

 Raphanistrum Twelve- striated. Insequalis Unequal. 

 Raphanus Seventeen- striated. Siphunculus Piped. 

 *Costatus Ribbed. *Legumen Pod. 



Granum Eight- striated. *Linearis Linear. 



*Radicula Bulbous-jointed. *Rectus Straight. 



