GASTEROPODA. 



113 



M. Adanson found abundance of these shells separated 

 from the animal in the sand at the mouth of the Niger. 



Am auk A. Moll. — Shell a lengthened oval, not umbili- 

 cated ; spire lengthened ; the aperture pear-shaped, and half 

 as long as the shell ; operculum thin and homy. Animal 

 with a small foot, which is neither longer nor broader than 

 the shell, the front part deeply notched; the eyes are 

 under the skin. — 1 species. 



A. Candida is found on the Greenland coasts ; it greatly 

 resembles Natica canaliculata. 



Laguncula. Benson. — Shell spiral, globular, with an 

 aperture large, entire, and rather long, the lips not com- 

 pletely joined; a deep winding umbilicus. Animal un- 

 known. — 1 species. 



L. pulchella from China. 



Family 17.— VELUTINACEA. 



The animals have a long retractile proboscis, rather 



short tentacula, which, [according to Loven J are connected 



by a membrane, with the eyes at the base ; the edge of the 

 i mantle very thick ; the tongue has in the middle a row of 



teeth, and on each side three rows of hooks. The shell is 

 | of various forms, with a strong horny epidermis, which 



often forms a hairy fringe ; the aperture is oval, or nearly 

 I round and entire, or forming an angle with the inner lip ; 

 ' no operculum, or only a small one, not sufficient to close 



the aperture. — Marine. 



Velutina. Gray. (Galericulum Brown ; 



Oxinoe, Couth.) — Shell thin; spire short, the | 

 i suture very deeply marked ; whorls few, the 



last very large, a pert Lire round and large, 

 I outer lip sharp. Animal, foot large, head broad, • 



tentacula awl-shaped, blunt; eyes at the base 



i 



