246 
LIMN^AD^. 
113. 1. Segmentina nitida. Glossy Segment Shell, 
(t. 8. f. 99.) 
Planorbis nitidus. Muller, ii. 163. 1774; Brap. p. 46. t. 2. 
f. 17 — 19. ; TurtoTiy Man. ed. 1. 116. f. 91. ; Pfeiffer, i. 82. 
t. 4. f. 12, 13.; Bossm. Icon. ii. 15. t. 7. f. 114, I15. — He- 
mithalamus lacustris. LeacJ^ Mollusc, p. 137. — H. nitidus. 
Leach, Ann. and Mag. N. II. xx. 269. — ’ JJ^autilus lacustris. 
Lightf. Phil. Trans, t. xxvi. (1786), t. 1. f. 1 — 7. ; Mont. 
p. 191. t. 6. f. 3.; Flem. E. Ency. vii. 86. — Helix llneata. 
Walker, Test. M. R. t. 1. f. 28. 1784. — Planorbis clausula- 
tus. Ferussac, 1820; Potiez and Michaud, Gall. i. 209.; 
Eesmoulins, Moll. Girond. n. 10. — Segmentina nitida. Flem. 
Effn. Ency. xii. — Helix nitida. Gmel. S. N. 3624. — 
Planorbis nautileus. Sturm, D. F. ; Kickx, Moll. Brah. 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. Brap.) 
— Planorbis lacustris. Forbes and Manley, 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- 
' 0^ 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. 
