GASTEROPODA. 7 



marshes where the water is brackish. The species found in the Crag are, however, 

 such as in the present day are frequenters of ponds and ditches, and were in all 

 probability conveyed to their present locality as dead and empty specimens. 

 Hitherto this genus has not been found in any older formation than the Eocene, 

 during which period it lived and flourished in great profusion. 



1. Liminlea palustris (?) Linn. Tab. I, fig. 9, a — d. 



Helix palustris. Gmel. Syst. p. 3658, 1782. 



Limneus palustris. Drap. Hist. Nat. des Moll. ter. et fluv. p. 52, tab. 2, fig. 40, 1805. 



Helix palustris. Mont. Test. Brit. p. 373, t. 16, fig. 10, 1803. 



Lymn^ea tenuis. Woodward. Geol. of Norf. t. 3, fig. 30, 1833. 



Lymn.eus palustris. Gray. 2d edit. Turt. p. 239, fig. 107, 1844. 



Lymneus palustris. S. Wood. Catalogue 1842. 



L. Testa elongato-ovatd, tenui : spird elevatd apice acuto ; anfractibus 4 — 5 convexis, 

 lavigatis ; aperturd ovatd. 



Shell elongato-ovate, thin, with an elevated spire and acute apex; whorls about 

 five, convex and smooth, aperture ovate, half the length of shell. 



Axis, f of an inch. 



Locality. Mam. Crag, Bramerton and Bulcham. Recent, Britain. 



Two or three belonging to Mr. Lyell, with one of my own, are all the fossil 

 specimens that I have been able to examine ; they do not satisfactorily agree with the 

 above recent species, although they resemble it more than any other with which I am 

 acquainted, and presentasort of intermediate formbetween it and L. pereger, having the 

 elevated spire of L. palustris and the convex whorls of L. pereger, or perhaps more 

 like gigantic specimens of L. trmicatuhs. The left lip, which in the recent shell is 

 a good deal reflected, is broken away in the Crag specimens, showing a small 

 umbilicus. This species I have found at Stutton and Clacton, precisely resembling 

 the recent form. 



2. Limn/EA peregra. Mull. Tab I, fig. 7, a — b. 



Buccinum peregrum. Mull. Verm. p. 130, No. 324, 1774. 

 Bulimus pereger. Bruguiere. Diet. No. 10, 1789. 

 Limneus pereger. Drap. Moll. pi. 2, fig. 34-37, 1805. 

 Helix peregra. Mont. Test. Brit. 1803. 



Limn.eus vulgaris. Rbssmasler. Icon. p. 97, t. 2, fig. 53-54, 1835. 

 — pereger. S. Wood. Catalogue 1842. 



L. Testa ovato-oblongd, tenui, fragili ; anfractibus quator, convexis; suturis profundis ; 

 spird mediocri, acuta ; labio reflexo, aperturd ovatd. 



Shell ovato-oblong, thin, and fragile, with four convex volutions and a deep 

 suture ; moderately elevated spire, and acute apex ; aperture elongato-ovate, with 

 a subreflected peritreme ; left lip covering the umbilicus. 



Axis, \ an inch. 



Locality. Mam. Crag, Southwold and Bramerton. Recent, Britain. 



One specimen of my own, with a few belonging to Mr. Wigham, obligingly sent 



