The Sea Snails. Bleeding Tooth 



The "bleeding tooth" is about i^ inches long; zigzag bands 

 of purple, red and black on a white ground make it a handsome 

 shell. There is great variation of pattern and colouring within 

 the species. The mollusk is a rapacious feeder upon seaweeds. 

 It is notable for the length of its rasping tongue. 



N. versicolor, Gmel., is gay with streaks and squares of 

 red and black, alternating with the whitish ground colour. 

 Numerous strong rounded ribs follow the spiral and are crossed by 

 zigzag markings. The species is smaller than the bleeding tooth 

 and may be recognised by the four teeth on the convex lip of 

 the columella. It is a West Indian species that ventures into 

 Southern Florida. 



The Tessellated Nerite (N. tessellata, Gmel.) has a checkered 

 dark and light surface like a chess board, or in less regular arrange- 

 ment, resembles the pattern shown in a snake's skin. Inside 

 the aperture the outer Up is toothed, and small teeth are borne 

 on the columellar lip. This solid, humped species is about an 

 inch long. It occurs on the southeast coast of Florida, frequent- 

 ing coral reefs and rocky beaches. 



The three species described above are the only North Ameri- 

 can representatives of the genus. 



Genus NERITINA, Lam. (NERITELLA, Humph.) 



Shells thin, globose, with short spire, usually smooth ; colu- 

 mellar lip broad, with fine marginal teeth, or smooth ; outer lip 

 sharp, not toothed within. 



This genus includes about two hundred species. They live 

 in rivers, except a few marine and brackish water species, and 

 some which are amphibious, clinging to roots of trees on river 

 margins. A few are terrestrial but live among the tree foliage 

 overhanging the water. Most of them are tropical or sub-tropical 

 in distribution. 



The shells look like dainty, polished replicas of the Floridian 

 "bleeding tooth." The animal within differs in no important 

 particular from those of the more sturdy genus, Nerita. As with 

 other tropical shells, there is much beauty of colour and pattern 

 exhibited in this large group. Many forms are ornamented with 

 spines. 



The European Nerite (N. fluviatilis, Linn.) inhabits the 



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