GASTEROPODA. 133 



Natica (Adans.), Lamarck. 

 Si/n., mammilla, Schm. Cepatia, Gray. Nacca, Risso. 

 Type, N. canrena, PI. VIII., fig. 1. 



Shell, thick, smooth ; inner lip eaUous ; umbilicus large, with a spiral 

 callus ; epidermis thin, polished ; operculum sub-spiral. 



Animal blind ; tentacles connate with a head veil ; front of the large foot 

 provided mth a fold {mentum), reflected upon and protecting the head ; operc. 

 lobe large, covering part of the sheU ; jaws horny ; lingual ribbon short ; 

 branchial plume single. 



The colom-ed markings of the naticee are very indestructible ; they are 

 frequently preserved on fossils. The naticce frequent sandy and gravelly bot- 

 toms, ranging from low water to 90 fathoms (Forbes). They are carnivorous, 

 feeding on the smaller bivalves (Gould), and are themselves devoured by the 

 cod and haddock. Their eggs are agglutinated into a broad and short spiral 

 band, very slightly attached, and resting free on the sands. 



Distr., 90 sp. Arctic seas, Brit., Medit., Caspian, India, Australia, 

 China, Panama, W. Indies. 



Fossil, 260 sp. Devonian — . S. America, N. America, Europe, India. 



Siih -genera, riaticojjsis, M'Coy. N. PhiUipsii. SheU imperforate ; inner 

 lip very tliick, spreading. Operc. shelly (Brit. Mus.). Carb. limestone, 7 sp. 

 Operculum, horny. 



Neverita, Risso. N. Alderi. Pig. 77. 



Lmiatia, Gray. N. AmpuUaria. Perforation simple; epidermis dull, 

 olivaceous. Northern seas. 



Globulus, J. Sby. (Deshayesia,t Raulin ; Ampullina, Desh. not Bl.) N. 

 Sigaretina. PI. VIII., fig. 2. Umbilicus narrow (rimate), lined by a thin 

 callus. Fossil, eocene. Brit., Paris. 



Polinices, Montf, (naticella Guild.) N. mammiUa. SheU oblong; callus 

 very large, filling the umbilicus. 



Cernina, Gray. N. fluctuata. PI. VIII., fig. 3. Globular, imperforate ; 

 inner lip callous, covering part of the body whirl. 



Naticella, Miiller. 19 sp. Fossil, Trias, S. Cassian. 



* Fis. 77. Natica Alderi, Forbes. Froir. an original drawing, communicated by 

 Joshua Alder, Esq. 



t Deshaijesia was founded on a specimen v ith prominences on the pillar. 



G 2 



