MOLLUSCA. 625 



Shell small, ovnl ; back convex, smooth, white, variously spfckled with 

 black, or dark brown ; spire inclined, lateral ; lip sliglitly denticulate. One 

 third of an inch Icing. Inh.ibits the rivers and streams of Europe. 



b9. Navicetlaetliptica. — The Oval Navicella. Plate Ixxv. fig. 1. Smo(jtli, 

 shining-, spotted and streaked with purple, blue, or brown ; covered with an 

 olivaceous epidermis ; spire curved, prominent, extending beyond the mar- 

 gin. One inch long. Inhabits rivers in the Isle of France. 



60. AmpuUaria Guyanensis. — The Guiana AmpuUaria. Plate Ixxv. fig. 

 2. Globular, thick, with unequal longitudinal striae ; covered with a fuscous- 

 brown epidermis ; inside golden. yellow. Three indies in diameter. Iuha> 

 bits the rivers of Guiana. 



61. Paludina vivipara. — The Viviparous Paltidina. Plate Ixxv. fig. 3. 

 Thin, ovate, ventricose, wrinkled longitudinally ; body with three brown 

 bands ; covered with an olivaceous epidermis. One inch and a half long. 

 Inhabits the rivers of Europe. 



62. Valvata piscinalis. — The Pond Valvata. Plate l.xxv. fis;-. 4 GlobU' 

 lai; conoid, somewhat trochus-shaped, deeply umbilicated ; apex obtuse ; 

 longitudinally wrinkled ; covered with a greenish-yellow epidermis. One- 

 fourth of an inch long. Inhabits the rivers and lakes of Europe. 



63. Pireiia terebralis. — The Dark Pirena. Plate Ixxv. fig. 7. Subulate, 

 longitudinally striated; outer lip expanded; covered with a deep black- 

 brown epidermis ; aperture white. Three inches long. Inhabits the rivers 

 of India. 



64. Melanopsis laevigata. — The Polished Melanopsis. Plate Ixxv. fig. 

 iS- Ovate, conical, smooth, of a chestnut-colour. Tliree fourths of an inch 

 limg. Inhabits the rivers of the Archipelago- 



65. Melania amarula. — The Crowned Melania. Plate Ixxv. fig. 8. 

 Ovate-obloug, thick; longitudinally wrinkled ; transversely striated at the 

 base of the body ; upper margin of the volutions crowned with triangular 

 tubercles, from which emanate ciliated spines ; colour deep chesnut, covered 

 with a black epidermis. One inch and a half long. Inhabits the rivers of 

 India. 



66. Lymnma stagnalis. — The Pond Lymna;a. Plate Ixxv. fig. 9. Ob. 

 (ong, body ventricose ; spire very acute and subulate ; aperture large and 

 ovate ; horn-coloured. Two inches long. Inhabits the ditches and ponds 

 of Europe. 



67. P/iysafontinalu.— The Fountain Physa. Plate Ixxv. fig. 6. Volu- 

 tions reversed, oval, diaphanous, glossy, horn-coloured ; spire short and 

 acute. Half an inch long. Inhabits the ditches and streams of Europe. 



68. Lutea /acunn.— The Ditch Lutea. Plate Ixxv. fig. 10. Very dia- 

 phanous, slightly wrinkled, and of a greenish horn-colour. Half an inch 

 long. Inhabits the ditches in Britain. 



69. P/atwrbis carinatus.— The Keeled Planorbis. Plate Ixxv. fig. 11. 

 Depressed ; upper side concave, with a keel round the middle of the body. 

 Three-fourths of an inch in diameter. Inhabits the ditches and lakes of 

 Europe. 



70. Planaiia albo.— The White Planaria. Plate Ixxv. fig. 17. White, 

 slightly wrinkled transversely; outer lip with a narrow niart,'in ocliiiul. 

 One fourth of an inch in diameter. Inhabits the coast of Dunbar, — 

 Scotland. 



71. Cyctoftomn elegans — The Elegant Cyclostoma. Plate Ixxv. fig. 12. 



3 G 3 



