204 PNEUMONOBRANCHIATA. 



74. 6. VERTIGO palustris. Marsh Whorl Shell, (t. 7. 

 f. 85.) Shell oval, ventricose, shining, brown, 

 whorls five ; aperture orbicular lunate ; margins 

 externally sinuated, with eight unequal teeth, 

 three of which are superior and between the lips 

 of the peristome. 



Pupa antivertigo. Drap. p. 60. t. 3. f. 32, 33. ? 

 Vertigo palustris. Leach, Mollusc, p. 128. t. 8. f. 10. 

 Alsea palustris. Jeffreys, Linn. Trans, xvi. 360. 

 Vertigo Montagua, Leach, MSS. 

 Pupa muscorum. Mont. T. B. 337. t. 12. f. 8.?; 

 Maton and Racket, Linn. Trans, viii. 183. ; 

 Pulteney, Dorset. 52. t. 19. f. 12. 

 Helix septemdentata. Ferus. Prod. 

 Jnhab. marshy situations. 



Animal grey-black, and shining; upper tentacles 

 short, inflated at the base, lower dot-like; front of 

 head proboscis-like. 



Shell smaller than the last, of a deep chestnut- 

 brown colour, with the margin of the aperture 

 whitish ; teeth three above and three below, and one 

 on each side, and often a ninth tuberc.ular tooth. 



It may easily be distinguished by the three very 

 discernible white teeth of unequal size within the 

 upper and truncated part of the aperture, whereas 

 there is only a single central one apparently visible in 

 the same position in V. pygm&a, and two in V. sub- 

 striata. The mouth varies with from six to nine teeth. 

 Dr. Leach first described and named this species 

 from some specimens which I found on Wimbledon 

 Common in 1817, and presented to the Museum col- 

 lection. It was first published as British by Ferussac 

 in his Concordance. 



