UNIVALVES TURBO. 89 



sists in its being entirely destitute of a pillar or columella 

 to connect its whorls; a circumstance so thoroughly op- 

 posed to the regular structure of all other turbinate shells, 

 must, of course, have created considerable doubt as to 

 Avliich genus it ought to be classed in; and some au- 

 thors have made no scruple to place it among the Serpu- 

 laB or Worm Shells. 



The False Wentle-trap, Turbo Clathrus, is easily dis- 

 tinguished from the True, by its being much more taper 

 or elongated, and is in reality a very common shell ; it is 

 usually placed in collections very close to the true one, 

 and thereby more clearly demonstrates the difference. It 

 is not umbilicate, and the whorls are more closely con- 

 nected. There are three varieties of this species: one is 

 pellucid with very thin ribs; the other has its lip produc- 

 ed into a beak; and some are spotted or dotted with 

 brown. They are found in the European and Indian seas, 

 in great plenty, from half an inch to two inches in length. 

 It is said, that, from the animal inhabiting these shells, the 

 ancients extracted a purple dye. 



Among the other rarities of this genus, the Pheasant 

 and Beauty varieties must not be omitted ; they are both 

 exceedingly scarce, and are mostly from Van Diemen's 

 Land, and other Islands of the South Seas. There is, per- 

 haps, no species of shells throughout the genera of Uni- 

 valves, which admits of so much real beauty and variety 

 as is manifest in the Pheasants. 



Many shells of this genus (commonly known as Need- 

 les or Screws) are exceedingly beautiful; their shape is 

 that of. a well proportioned spire, with thirty or fortv 

 whorls gradually tapering or diminishing from the base 

 to the very extreme tip or apex of the shell, and there 

 ending in a most acute point, forming in their course the 



