214 POPULAR CONCHOLOGY. 



ing, the upper whorls being blackish, whilst the 

 apex and two last are red or flesh-coloured. 

 Many species are very iridescent at the mouth 

 and under the epidermis. There are some spe- 

 cies common on our coasts, but none attain the 

 beauty of the foreign varieties. 



80. Monodonta. — Shell oval or pyramidal ; 

 lips disunited at the upper part, the 

 right being occasionally striped with- 

 in, and the left having a tooth-like 

 process, whence the name is de- 

 rived; operculum horny and thin. 

 Animal, head distinct, having two tentacula, 

 with eyes at the base ; foot short. — 25 species, 

 recent. 



These shells are found in most seas ; they 

 seem to form a connecting link between the 

 Trochus and the next genus, which they much 

 resemble. 



81. Turbo. — Shell rather turreted, base not 

 flattened ; mouth round ; lips not 

 united ; outer lip thin ; an opercu- 

 lum, shelly and solid. Animal, 

 head having two pointed tentacula, 

 with eyes at the base ; foot short. 

 — 34 species recent, and 4 fossil. 



