156 POPULAR BRITISH CONCHOLOGY. 



C. trachea is so named from the rings round the tube of 

 the shell giving it the appearance of a piece of wind- 

 pipe. 

 C. glalrum is smooth. 



II. TuRRiTELLA communis. — This more elegant mollusc, 

 with his spirallj-flated shell, winding down in many an ob- 

 lique gyration from its pointed apex, would look with scorn 

 on his humble neighbour the CcEcum, did he but know that 

 so insignificant a creature was placed beside him, not only 

 in the walks of submarine life, but also in the "order of 

 of jN^ature," as guessed at by the ablest investigators. Yet 

 our solitary species, although beautifully sculptured and 

 sometimes prettily marked with darker touches on a brownish 

 ground, has not much to boast of in comparison with some 

 of his congeners of foreign parts, whose tapering spires and 

 noble pyramidal columns have been so suggestive of elegance 

 in architectural design. 



The shell of T. communis attains, when well developed, 

 the length of two inches to two and a half; it has about 

 fourteen whorls with three or four spiral ridges ; operculum 

 horny, round, many-spired. The head of the animal is pro- 

 duced into a muzzle-shaped, squarish proboscis, notched in 

 front, with long narrow tentacles having eyes at their base; 

 the foot is short, square in front, blunt behind, and grooved 



