246 LIMN^AD^E. 



113. 1. SEGMENTINA nitida. Glossy Segment Shell, 

 (t. 8. f. 99.) 



Planorbis nitidus. Miiller, ii. 163. 1774; Drap. p. 46. t. 2. 

 f. 17 19. ; Turton, Man. ed. 1. 116. f. 91. ; Pfeiffer, i. 82. 

 t. 4. f. 12, 13.; Rossm. Icon. ii. 15. t. 7. f. 114, 115. He- 

 mithalamus lacustris. Leach, Mollusc, p. 137. H. nitidus. 

 Leach, Ann. and Mag. N. II. xx. 269. Nautilus lacustris. 

 Light/. Phil. Trans, t. xxvi. (1786), t. 1. f. 17.; Mont. 

 p. 191. t. 6. f. 3.; Flem. E. Ency. vii. 86. Helix lincata. 

 Walker, Test. M. R. t. 1. f. 28. 1784. Planorbis clausula- 

 tus. Ferussac, 1820; Potiez and Michaud, Gall. i. 209.; 

 Desmoulins, Moll. Girond. n. 10. Segmentina nitida. Flem. 

 Edin. Ency. xii. Helix nitida. Gmel. S. N. 3624. 

 Planorbis nautileus. Sturm, D. F. ; Kickx, Moll. Brab. 66. 



Segmentina lineata. Flem. Brit. Anim. 279., Treat. 

 Moll. Anim. t. 7. f. 13.; Gray, Man. 271. t. 8. f. 99. 

 Planorbis complanatus. Poiret, Prod. 93. (not Linn. Drap.) 

 Planorbis lacustris. Forbes and Hartley, B. M. iv. 162. 

 t. 128. f. 123. Segmentina lacustris. Swains. Malac. 338. 



Planorbis lineatus. Jeffreys, Linn. Trans, xvi. 389.; 

 Alder, 114. 



In stagnant waters, on aquatic plants. 



Shell hardly a quarter of an inch in diameter, 

 highly polished and smooth, of a chestnut or reddish- 

 brown colour, flattish and semitransparent ; volutions 

 Fig 59 four, the outer one very large in pro- 

 45^ ^>K portion, and marked with two or three 

 ^*^ whitish transverse lines exhibiting the 

 internal partitions ; the upper surface very convex, 

 with a deep umbilicus in the centre, the under side 

 nearly flat, and umbilicate in the centre ; the circum- 

 ference slightly carinate ; aperture oval, inclining to 

 triangular, with the peristome interrupted. 



Except for its internal semiconcamerated partition, 

 this shell exactly resembles the Planorbis fontanus , 

 but is larger. 



