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POPULAR CONCHOLOGY. 



This very remarkable shell, both in appearance and the 

 habits of its inhabitant, is found on the shores of Portugal, 

 Africa, India, and also in the Mediterranean. They are 

 often found twisted together in great numbers in the seas 

 near Senegal. The only species, V. lumbricalis, has the 

 spire generally regular in its formation, but the rest of the 

 whorls separated, and irregularly twisted ; they are attached 

 by the pointed extremity of the spire. 



Magilus. Montf. — Shell ventricose ; spire short, con- 

 sisting of three or four whorls ; aper- 

 ture longer than wide, without any 

 notch, but an angle at the base ; the 

 last whorl, abandoning altogether the 

 spiral form, produces a long tube, 

 which is compressed laterally, espe- 

 cially on the side of the base of the 

 shell ; aperture elliptical. Animal, 

 head small, prolonged on each side 

 into two short tentacula ; eyes at the 

 base; proboscis obtuse; foot muscu- 

 lar; operculum horny. — 2 species. 



When in the young state this 

 curious shell presents all the charac- 

 ters of a regular spiral univalve. The 

 animal establishes itself in the exca- 

 vations of madrepores ; and as the ^ 

 coral increases around it, the Magilus 

 is obliged, in order to have its aper- 

 ture on a level with the surrounding 

 surface, or near it, to construct a tube, the growth of the 

 coral determining its length. As this tube goes on in- 

 creasing, the animal abandons the spiral for the tubular 

 part of the shell ; and in the operation it leaves behind no 



Magilus antiquus 



