NERITINA. 47 



11. 194. ; Drap. p. 31. 1. 1. f. 1 14. ; Brard, p. 194. t. 7. f. 

 9. 10. 12. ; Mont. p. 470. ; Turt. Diet. 127. ; Forbes and 

 Hanley, B.M. iii. 3. t. 71. f. 1. 2. t. H. H. f. 1. Nerita 

 fontinalis, Brard, Coq. Par. 196. t. 7. f. 11. Neritina 

 zebrina, N. peloponnensis. N. numidica, N. Mittreana. 

 Recluz. Neritina intexta. Villa. Neritina Sardon and 

 N. trifasciata. Menke. Neritina Hildreichii. Schwerz. 



Nerita Bourguignati. Recluz, Jour. Conch. 1825, 293. 



Nerita Prevostiana. Pfeiffer, D. Moll. iii. 49. t. 8. f. 11, 



12. Nerita thermalis. Boubee in Bull, 1833, 12. Theo- 

 doxus lutetianus. De Montfort, ii. p. 351. Neritina 

 fontinalis. Brard, Hist. C. 196. t. 7. f. 11. 13. ; Pet. Gaz. 

 t. 91. f. 3.; List Conch, ii. 1. 38. ; Swamm. B. N. 80. t. 10. 

 f. 2. Neritina dalmatica. Sow. C. Illus. f. 57. Neritina 

 variabilis. Hecart. Moll. Vail. 1. 146. 



In slow rivers, adhering to stones. 



Animal white ; head and back of the neck blackish ; 

 hinder part of the foot sometimes black spotted ; ten- 

 tacle long, white, with blackish line. 



Shell about three eighths of an inch long, and two 

 broad, convex above and flat underneath, obscurely 

 striate transversely, of a greenish or whitish colour, 

 variously chequered with spots or bands of white, 

 brown, purple, or pink; spire consisting of three 

 volutions, the first very large, oblong, and oblique, 

 the others small and lateral; aperture horizontal, 

 semielliptic, with the margin sharp and entire ; pillar 

 white, transverse, sloping down to a sharp edge, and 

 quite entire ; operculum semilunar, yellowish, with 

 an orange border, and underneath is a strong raised 

 grooved spire at one end. 



The shells are often covered with calcareous in- 

 crustations, deposited by the water, which make 

 them look like pieces of dirt, and thus escape being 

 seized on by the fish. 



The continental conchologists have described se- 



