THE PELICAN'S FOOT. 



389 



a polished bone-like epidermis. The color of the Spined Neritina is deep green-black 

 on the exterior and blackish white within. The shell is thick and solid at the aperture, 

 but becomes thinner towards the interior. 



THE topmost figure represents another species of this genus, the CROWN NERITINA, 

 given for the purpose of showing the animal as it appears while crawling. The color 

 of this shell is gray, diversified with dark streaks. One species of the genus, the RIVKR 

 NERITINA (Neritina Jhiriatilis), is found in the rivers of England. 



THE two curious shells represented in the accompanying illustration are examples of 

 another family, that of the Clubs, or Cerithiadae. The shell of the Cerithites is spiral, 

 more or less elongated, and the operculum is horny and spiral. The tentacles are 

 placed rather far apart, and the eyes are set on very short footstalks. These creatures 

 inhabit either marine, brackish, or fresh water. 



CROWN NERITINA. -Nerttlat corona. SMOOTH NERITA.-Afer/te pollta. 

 SPINED NERlTINA.-jVertt/fla splnosa. NATICA.-Mrt/ca Chemnltzll. NATICELLA. Afetfce//* porcelaaa. 



THE left-hand figure represents the PELICAN'S FOOT, sometimes called the SPOUT- 

 SHELL, on account of the manner in which the aperture is lengthened into a kind of spout 

 in front. This shell has a rather elongated spire, and is considerably tuberculated on the 

 exterior. As the animal approaches maturity, it adds fresh substance to the lip, until it 

 bears some resemblance to the webbed foot of an aquatic bird. The animal has a short 

 and rather abrupt muzzle, and moderately long, cylindrical tentacles, having the eyes set 

 on protuberances near their base. Only three species of this genus seem to be at present 

 known, but they have a wide range of locality, being spread over the greater part of the 

 world, and found at various depths, sometimes being taken in a hundred fathoms of water. 



The color of the Pelican's Foot is white, with a tinge of pink, and white inside. The 

 shell is thickly and strongly made, and heavy in proportion to its weight. It is not a 

 large species, seldom measuring more than two inches in length. 



