210 
LIMNiEADiE. 
a proof of a difference in species, while it may be 
the cause of the variation. 
The eggs are like those of L. stagnalis. (See 
Pfeiffer^ t. 8. f, 18.) 
These animals are extremely variable in size and 
colour, according to the locality in which they are 
found, and the abundance of their food. 
Mr. Alder observes that a variety of a much 
smaller size is found on the margins of rivers, and 
another is found in mountain streams. 
94. 5. Limk^^us truncatulus. Ditch Mud Shell. — 
Shell oblong-oval, pointed, brittle, perforated, 
with six or seven rounded and deeply divided 
volutions, striolate longitudinally and across ; 
mouth ovate-oblong, (t. 9. f. 108.) 
Helix fossaria. Mont. 372. t. 16. f. 9.; Linn. Trans, vlii. 
t. 5. f. 9. — Buccinum truncatulum. Muller.^ Verm. ii. 130. 
— Helix truncatula. Gmelin., 3659. ; Dillw. R. S. 967. — 
Limneus minutus. Drop. p. 53. t. 3. f. 5, 6.; Alder., Cat, 115. 
— - Bulimus truncatus. Brug. E. M. i. 310. — ^ Limneus fos- 
sarius. Turton., Man. ed. 1. 124. f. 108. — Lymneus minutus. 
Brard^ p. 138. t. 5. f. 8, 9. — Lymnsea minuta. Lamarck., 
vi. ii. p. 162. — Stagnicola minuta. Ijeach., Mollusc, p. 143. 
— Lymnsea fossaria. Flem. Edinh. Ency. vii. 77., B. A. 
274. — • Limneus truncatulus. Jeffreys., Linn. Trans, xvi. 
377. — Limnmus minutus. Rossm. Icon, i. 100. t. 2. f. 57. — 
Bulimus obscurus. Pioret., Prod. 35. — Limnophysa minuta. 
Fitz. 113. — “ Limnasus truncatulus. Forbes and Hanley., 
B. M. iv. 177. t. 124. f. 3. — Lymnea minuta. Schub. and 
Wagner., f. 4. t. 34, 35. — Limnaeus limosus. Cantr. Mhn. 
Brux. 1836, 157. — Limnea minuta. Grass. Moll. Franc, t. 4. 
f. 44. — Limnsea truncatula. Alder., Moll. 42. — Lymnea 
oblonga. — Pat. Moll. Vog. 60. — Limnea microstoma. Drouet. 
— Limnea Doublieri. Req. 
Var. 1., conic-oval, less glossy brown and smooth. Drap. 
p. 53. t. 3. f. 7. 
Monstrosity with the lower volution flattened at top, in the 
centre of which are sunk the other volutions. 
