GASTEROPODA. 123 



Natica (Adans.), Lamarck. 

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

 Ti/2^e, N. canrena, PI. Till., fig. 1. 



.- <- >j 



Shell, thick, smooth ; inner lip callous ; 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 with a fold {mentum), reflected upon and protecting the head ; operc. 

 iobe large, covering part of the shell ; jaws horny ; lingual ribbon short ; 

 branchial plume single. 



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

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

 toms, ranging fi'om low water to 90 fathoms (Forbes). They are carnivorous, 

 feeding on the smaller bivalves (Gould), and are themselves devoujed 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! 



Sub-genera, naticopsis, !M'Coy. N. Phillipsii. Shell imperforate ; inner 

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

 Operculum, horny. 



Neverita, Risso, N. Alderi. Fig. 77. 



Lunatia, Gray. N. Ampullaria. Perforation simple; epidermis didl, 

 olivaceous. Northern seas. 



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

 Sigaretina. PL YIII., fig. 2. Umbilicus narrow (rimate), lined by a thin 

 callus. Fossil, eocene. Brit., Paris. 



Polinices, Monti, (naticella Guild.) N. mammilla. Shell oblong ; callus 

 very large, filling the umbilicus. 



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

 inner lip callous, covering part of the body whirl. 



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



* FIr. 77. Natica Alderi, Forbes. From an original drawing, communicated by 

 Joshua Alder. Esq. 



t Dcshaijesia was founded on a specmien vith prominences on the pillar. 



G 2 



