GASTEROPODA. 



91 



cial perforation. C. cervina is supposed to be the largest 

 species, being more than four inches in length. It inhabits 

 the American seas. Philippi states that these molluscs 

 are very timid, and that they live on sea weeds. 



Erato. Risso. — Shell, small, ovate, with a scar or groove 

 down the back, otherwise smooth ; notched at the ^ 

 base ; spire rather prominent ; last whorl large ; Jr 

 mouth narrow ; both lips more or less finely toothed, Erato 

 the outer generally swollen in the middle. Animal, 

 very like that of Cyprcea, but the lobes of the mantle are 

 thin. — 8 species, also fossil. 



Small shells, principally found in the Mediterranean 

 Sea, the shores of the West Indies, China, and Britain. 



Ovula. Brug. — Shell egg-shaped, sometimes spindle- 

 shaped ; inner lip without teeth ; outer 

 slightly wrinkled, the extremities generally 

 projecting ; spire quite hidden ; no epidermis. 

 Animal, very similar to that of Cyprcea, 

 but the ligual ribbon short. — 48 species*; 

 also fossil. 



In some species the ends of the mouth 

 are so much lengthened as to make the shell 

 fusiform ; this is the case with O. volva, the 

 weaver's shuttle. O. p alula, the English 

 species, is very thin. O. oviformis, represented above, 

 is perfectly white outside, and of an orange-brown within ; 

 the young shell is as thin as paper. This genus chiefly 

 inhabits the Indian and Chinese seas ; it is also found 

 in the Black Sea and the Mediterranean. 



Marginella. Lam. (Porcellana Adanson.) — Shell oval, 

 smooth ; spire short, more or less depressed ; mouth nar- 



* Sowerby's Thesaurus. 



