NERITA. NEEITE. 127 



7- Kerita fiuviatilis. River Nerite. 



Lister, pi. 141. f. 38, and j>l. 607- f. 43, 44 Pennant, 

 pi. 90. f. 2-^Da Costa, 'pi. 3. f. 8 Donovan^ pi. 16. f. 2- 

 Dorset Cat.pl. 16. f. 17, 18. 



Shell somewhat oval, semitransparent, often covered 

 with a greenish or brownish skin, slightly wrinkled across, 

 variegated with purplish-brown, white, pink, or pale brown, 

 in spots, streaks or bands : spires three, the first volution 

 very large and produced at the outer-lip ; the others small 

 but well denned, placed laterally, and ending in a fine point : 

 aperture half-moon shaped ; the outer lip thin 5 pillar-lip 

 white, polished, broad, with an acute entire edge ; diameter 

 three-eighths of an inch. 



In slow rivers, v. v. 



8. Nerita tuberosissima. Tiibercled Nerite. 

 Montagu, pi. 29. f. 5. 



Shell white, transparent, somewhat orbicular, with a 

 very minute point : spires three or four ; the first very 

 large, and marked with four circular tubercled ridges ; the 

 others very small and lateral : perforation large : diameter 

 about the eighth of an inch. 



Firth of Forth : very rare. 



9. Nerita pellucida. Linn. Trans, iii. p. 67, 



Shell smooth, transparent, with three volutions : mi- 

 nute. 



On the Pembrokeshire coast. 



10. Nerita alba. Linn. Trans, iii. p. 67. 



Shell smooth, semitransparent, with two volutions ; mi-r 

 nute. 

 On the Pembrokeshire coast. 



B. With the pillar-lip toothed, 11. 



11. Nerita vi'-ginea. Spotted Nerite. 

 Lister, pi. 606. f. 35 to ^7. 



Shell oval, smooth, polished, white with a pale ferrugi- 

 nous tinge, elegantly marked with black zigzag lines run- 

 ning in various directions : spires three or four, hardly di- 

 stinguishable from each other, with a blackish line running 

 round the junctions, and a little carious at the tip : aper- 



