'SPINED KERIT1 NA. Neritina apinosa. 



CKOWN NERIT1NA. Neritina corona. 

 NATICA. Ndtica Chemnitzii. 



SMOOTH NER1TA. tier-cta polUa. 

 NATICELLA. Naticella porceldna. 



bone-like epidermis. The colour of the Spined Neritina is deep green-black OR 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 NEIUTINA, 

 given for the purpose of snowing the animal as it appears while crawling. The colour of 

 this shell is grey, diversified with dark streaks. One species of this genus, the EIVEK 

 NEKITINA (Neritina fluvidtilis), 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 Cerithiadse. 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. 



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 colour 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. 



