200 POPULAR BRITISH CONCHOLOGY. 



31. purpurea : shell brownish-purple, speckled with white ; 

 spire long ; whorls rounded ; ribs crossed (in one va- 

 riety they are notched out into produced points). 



M. Leufroyi : shell white or brown, with a hght band ; ribs 

 few, rounded ; w^horls rounded, crossed with spiral striee. 



3L linearis : shell rather short, with brown raised lines run- 

 ning over rounded longitudinal ribs. 



M. gracilis : animal white, marked with pink spots and 

 lines ; foot slender, pointed behind ; tentacles short ; 

 shell brown, with a narrow white spiral band ; whorls 

 rather turreted, their upper part bluntly ribbed ; canal 

 rather produced. 



31. nehula : yellow-spotted, with the back of the foot notched; 

 shell brown ; spire and last whorl conical ; aperture 

 very short in proportion to the spire ; ribs obtuse. 



31. hrachystoma : the animal exhibited great activity in con- 

 finement, freely exhibiting his body, which is speckled 

 with yellowish flakes ; the siphon produced ; the foot 

 long, tapering to the back, bilobed in front ; eyes placed 

 about the middle of short tentacles ; shell very small, 

 pale, with raised spiral lines across blunt angulated 

 ribs ; aperture very short indeed in proportion to the 

 spire. 



